GAS FIRED HIGH EFFICIENCY LOW NOx BOILERS

GAS FIRED HIGH EFFICIENCY LOW NOx BOILERS

SINGLE UNIT OUTPUTS 204 kW-472 kW

INSTALLATION & OPERATING INSTRUCTIONS

Please contact the Technical Department if further clarification on any point is required.

35 Nobel Square Basildon

Essex SS13 1LT

01268 591010 Phone 01268 728202 Fax

V. 01/01/2000GR

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INDEX1

DESCRIPTION SECTION ONE : INTRODUCTION 1.1 RECOMMENDATIONS 1.2 FIRST FIRING 1.3 USE AND MAINTENANCE SECTION TWO : STANDARDS 2.1 CERTIFICATES SECTION THREE : GENERAL REQUIREMENTS 3.1 REQUIREMENTS SUMMARY 3.2 SCALING AND CORROSION 3.2.1 OLD INSTALLATIONS 3.2.2 NEW INSTALLATION 3.3 THERMAL SHOCK 3.4 WORKING PRESSURE 3.5 FLUE SYSTEM 3.6 VENTING 3.7 USE AND MAINTENANCE SECTION FOUR : DESCRIPTION 4.1 SECTION AND PLAN ELEVATION OF DUPLEX BOILER 4.1.1 DUPLEX BOILER MODELS DUPLEX - 290, 360 4.1.2 DUPLEX BOILER MODELS DUPLEX - 430, 500 4.2 HEAT EXCHANGER 4.3 BURNER 4.3.1 KIT PILOT BURNER AND CONTROL FLAME 4.3.2 MAIN BURNER 4.4 GAS CONNECTION 4.5 CONTROL PANEL 4.6 BOILER FLUEWAY SYSTEM 4.7 POSITION OF THE VARIOUS COMPONENTS 4.8 TECHNICAL DETAILS 4.9 DIMENSIONAL DATA

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INDEX2 DESCRIPTION 4.10 ELECTRICAL DETAILS 4.10.1 SATRONIC CONTROL SYSTEM 4.10.2 ELECTRICAL WIRING DIAGRAM FOR DUPLEX BOILER, MODELS 220-430 4.10.3 ELECTRICAL WIRING DIAGRAM FOR DUPLEX BOILER, MODEL 500 4.11 MANUFACTURING BOILER LABEL SECTION FIVE : INSTALLATION 5.1 THE BOILER ROOM 5.2 AIR SUPPLY & VENTILATION 5.2.1 AIR SUPPLY BY NATURAL VENTILATION 5.2.2 AIR SUPPLY BY MECHANICAL VENTILATION 5.3 BOILER BASE 5.4 MODULAR CONNECTION 5.5 ELECTRICAL CONNECTION 5.6 MOUNTING THE BOILER 5.7 SYSTEM WATER 5.7.1 CLEANSING OF OLD SYSTEMS 5.7.3 WATER QUALITY 5.8 WATER FLOW RATE AND TEMPERATURE RISE 5.9 OPERATING WATER TEMPERATURES 5.10 BOILER HYDRAULIC RESISTANCE 5.11 HYDRAULIC CONNECTIONS 5.11.1 INERTIAL TANK 5.12 SYSTEM SCHEMATICS 5.12.1 TYPICAL SINGLE BOILER INSTALLATION 5.12.2 TYPICAL INSTALLATION OF SINGLE BOILER (DHW OR A VERY OLD SYSTEM) 5.12.3 TYPICAL MULTIPLE INSTALLATION (HEATING, DHW) 5.12.4 TYPICAL MULTIPLE INSTALLATION, FOR DHW PRODUCTION, OR A VERY OLD SYSTEM, OR A HEATING SYSTEM OPERATING AT LOW TEMPERATURES 5.13 GAS SUPPLY

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INDEX3 DESCRIPTION 5.14 FLUE SYSTEM 5.14.1 POSSIBLE FLUE CONNECTION FOR BOILER MODEL DUPLEX-220 TO DUPLEX-430 5.14.2 FLUE OUTLET MODEL DUPLEX-500 SECTION SIX : START UP AND CONTROL 6.1 PRE-START CHECKS 6.2 MEASURE INSTRUMENTS 6.3. PREVIOUS CHECKINGS ON THE BOILER 6.4 ADJUSTING PILOT BURNER 6.4.1 CHECKING THE PILOT BURNER 6.4.2 CHECKING THE COMBUSTION OF PILOT BURNER 6.5 PRIMARY AIR DAMPER MOTOR 6.6 LOW - HIGH FIRE DELAY TIMER 6.7 FLUE DAMPER 6.8 ADJUSTMENT OF SECOND STAGE (HIGH FIRE) 6.9. ADJUSTMENT OF FIRST STAGE (LOW FIRE) 6.10 WARNINGS ON COMBUSTION HIGH AND LOW FIRE : 6.11 READINGS ON THE BOILER SECTION SEVEN : FAULTS DURING OPERATION 7.1 POOR COMBUSTION 7.2 FAULTS THAT CAUSES THE BOILER NOT TO WORK 7.2.1 WHITE SECTOR. 7.2.2 BLUE SECTOR. 7.2.3 RED SECTOR. 7.2.4 YELLOW SECTOR 7.2.5 GREEN SECTOR 7.2.6 GREEN SECTOR SECTION EIGHT : MAINTENANCE 8.1 CLEANING THE BURNER AND THE COMBUSTION CHAMBER 8.2 CLEANING THE HEAT EXCHANGER 8.3 CHECKING BOILER SECTION NINE : LIST OF BOILERS COMPONENTS

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SECTION ONE INTRODUCTION The DUPLEX boiler is a product made by a manufacturer of more than thirty years experience in the heating market. The policy behind the development of the DUPLEX boiler is to provide an appliance which gives the benefits of space saving, reliability, high efficiency and reduced harmful emissions. The DUPLEX boiler is constructed from high grade materials to ensure a long and efficient service life. The DUPLEX boiler is a high-efficiency boiler: - CERTIFICATE CE, As gas boiler, according to European Directive 90/396/EEC - HIGH EFFICIENCY: The DUPLEX boiler obtains combustion efficiencies between 94 -

96% nett, therefore it has obtained the certificate CE of 3 stars (***). Certificate AFNOR Nr. 49AR001R according to directive 92/42/EEC. The flue gas temperatures are about 900C in the low fire stage, and below 1200C in the high fire stage.

- HIGH OUTPUT: Five models offering 204, 275, 340, 408 and 472 kW - CERTIFICATE OF COMBUSTION LOW NOX: The DUPLEX boiler has been granted

the " Combustion Label Clean", Certificate GASKEUR, - - 100% PREMIX COMBUSTION - HIGH / LOW FIRE: Each DUPLEX boiler has a 2 stage burner system which, according

to demand from external system controls, will operate at either 60% or 100% of output. This allows closer matching of burner power to varying system loads, and avoids nuisance cycling. The burner output is adjusted via a damper motor driven system, comprising gas and air interlinked butterfly dampers.

- COMPACT DIMENSIONS: The DUPLEX boiler is designed around a unique multi water

tube heat exchanger, which provides an exceptional heat transfer surface area. This allows high output to dimension ratio to be achieved, and creates an appliance which is ideal for applications where plantroom space is restricted. Space saving due to the reduced dimensions of the boiler. Foot prints less than 0.5 m2, and heights less than 1.3 m.

- LOW GROSS WEIGHT: Saving of transportation by its reduced weight and

dimensions. A boiler of heat output of 472 kW has a weight of 350 kg. - Saving of movement and installation. - Reduction of the heat losses by boiler radiation. Thanks to its reduced dimensions (1/3

of a conventional boiler) it obtained an important reduction of the radiant surface of the boiler.

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- COMPREHENSIVE CONTROL AND INSTRUMENTATION: The functions of the boiler

are managed by a comprehensive control centre which employs industry standard components and provides full operational temperatue and safety control, as well as monitoring of burner status, temperatures and running hours, all housed in a user and service engineer friendly panel at the top of the appliance.

- FULLY AUTOMATIC IGNITION: Electronic ignition. Flame Rectification Control . Pilot

only acts as support in the starting of the boiler. - REMOTE INDICATION: As an optional extra, the boiler control panel can provide volt

free alarm connection points for burner lockout, overheat trip & burner run. Easily connection to BMS or similar remote monitoring panel.

- LOW WATER PRESSURE DROP. - DUPLEX boilers can be used as individual appliances or in multi or modular

configuration to accurately and efficiently meet system loads. - DELIVERY: DUPLEX boilers are fully factory assembled and tested and require no site

assembly. The product is delivered to site packed within a sturdy pallet-mounted crate. 1.1 RECOMMENDATIONS These instructions are designed to assist the installation engineer with the installation of DUPLEX boilers. The guidance given in this manual should be carefully followed to ensure correct operation of boiler. Specific attention must be paid to :

* The system design. * System water quality and water treatments. * The flue system. * The gas supply. * The electrical connections. * Regular maintenance.

1.2 FIRST FIRING It is recommended that the first firing of a DUPLEX boiler be carried out by the supplier or a suppliers approved engineer. 1.3 USE AND MAINTENANCE The installer should instruct the user on correct operation and advise on the importance of regular maintenance. SECTION TWO STANDARDS The installation of the DUPLEX boiler must be carried out by a competent engineer in accordance with the relevant requirements of the Gas Safety (Installation & Use)

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Regulations 1996, Health & Safety Executive Regulation PM5, Act, Building and IEE Regulations, Local Authority, Local Gas Undertaking, Local & National Water Authority, Fire Authority, Regulations and Insurance Company Requirements. The following British Standards/Codes of Practice are applicable : BS 6644 Installation of gas fired hot water boilers of rated input between 60 kW and 2 MW

(2nd and 3rd family gases) BS 6880 Code of Practise for low temperature hot water heating systems of output greater

than 45 kW CP341.300-307 Central Heating by low pressure hot water. CP 342 Part 2. Centralised hot water supply. CIBSE Guide Reference Sections B7, B11 and B13 IGE/UP/2 Gas installation pipework, boosters and compressors on industrial and commercial

premises. The efficient life of a boiler is directly relative to correct operating conditions being achieved and maintained. The installation and maintenance of the boiler must be carried out strictly in accordance with the instructions contained in this manual. The manufacturers guarantee will not apply if : * the instructions for installation and maintenance are not followed strictly. * the boiler is used incorrectly. * the boiler is not protected from corrosion, thermal shock, over pressure and lack ofwater

or water flow. 2.1 CERTIFICATES DUPLEX MODEL

220

290

360

430

500

GAS BOILERS DIRECTIVE 90/396/EEC

49AO1

31

49AO1

29

49AO1

31

49AO1

31

49AO130

EFFICIENCY BOILERS DIRECTIVE 92/42/EEC

49AR001R

CLEAN COMBUSTION

GASKEUR G96/027

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SECTION THREE GENERAL REQUIREMENTS 3.1 REQUIREMENTS SUMMARY CONCEPT

DETAIL

VALUE

pH

between 8,5 and 10

Total hardness (TH)

lower than 60 ppm

Turbidity (MES)

lower than 10 mg/l

Iron (mg/l)

lower than 1 mg/l

Oxygen (mg/l)

lower than 0,1 mg/l

Resistivity

greater than 2,000 Ohm / cm

WATER PARAMETERS

Conductivity

lower than 500 µS/cm

Maximum Flow Temperature

90 0C

OPERATING WATER

TEMPERATURES Minimun return Temperature

55 0C

OPERATING PRESSURE

Maximum

4.85 bar

POWER SUPPLY

220/240 V, 50 Hz, AC and earthed Chimney Draught (when cold)

0 mm.w.c.

Flue Temperature, Low Fire

Near 900C

FLUE SYSTEM

Flue Temperature, High Fire

Near 1200C

3.2 SCALING AND CORROSION In order to avoid scaling and corrosion : * Attention must be paid to the type of water supplied. * Frequent draining and refilling of the water of the system should be avoided. * The installation of a water meter in the filling section of the primary circuit is highly

recommended, and should be regularly checked. PRE-TREATMENT OF THE WATER SUPPLY FOR THE PRIMARY CIRCUIT IS ABSOLUTELY ESSENTIAL IN THE FOLLOWING TYPES OF INSTALLATION * In very large installations. * Where there is frequent introduction of new water into the system. * When there are repeated partial or total draining of the system.

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3.2.1 Old installations Before replacing boilers of an old installation by new boilers, must be proceed by: Removal of sludge and debris from circulating water of heating system, by means: * Clean of the installation primary circuit (if a chemical product is used it must be

compatible with the installation materials). The drain must be done through a position lower than the boiler (and not through the new boilers).

* Removing and filtering equipments for trapping particles. * Install a water treatment and a water meter in the inflow section of the primary circuit. Instead of the above actions, in order to avoid that the system sludge, debris magnetite sludge affect the new boilers, the boiler must be separated from the old parts of the system by means of a plate heat exchanger (see drawings included). 3.2.2 New installation Cleaning of oils, welding particles, sand... A water quality control must be done in order to check if it has the proper values. 3.3 THERMAL SHOCK The exit/flow temperature of the water in the boiler must never under any circumstances exceed 900C. The return temperature must always be greater than 55oC 3.4 WORKING PRESSURE The maximum pressure permitted during boiler operation is 4.85 bar. This is indicated on the boiler name-plate and must be never exceeded under any circumstances. Precautions must be taken against this ocurring even through accident. Ensuring conformity within the system is the responsability of the fitter. 3.5 FLUE SYSTEM Detailed recommendations for the flue are given in BS6644 and British Gas IM/11. The necessary chimney diameter can be calculated as a function of the height, material, number of bends, horizontal lenght. The chimney draught (when cold) must be 0 mm.w.c.

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3.6 VENTING All necessary precautions must be taken to avoid : * Residual deposits in the lower part of the boiler. It is advisable to incorporate a 1.6 mm2

strainer in the return pipe. * Air accumulation in the upper part of the boiler. Three manual release points are located

in the upper water chamber of the boiler to perform the venting operation 3.7 USE AND MAINTENANCE The installer is required to advise the user that : * Prior to or immediately after start-up, it is absolutely essential to carry out a cleaning

and flushing operation on the system and top-up the water treatment. * it is recommended to avoid draining the system. In the case of systems which utilise anti-freeze and/or additives, these must be of a type compatible with the materials which comprise the boiler and system, so as to avoid : * chemical corrosion * galvanic action * mechanical wear * changes in viscosity

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SECTION FOUR DESCRIPTION 4.1 SECTION AND PLAN ELEVATION OF DUPLEX BOILER 4.1.1 DUPLEX BOILER models DUPLEX-290,360

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4.1.2 DUPLEX BOILER models DUPLEX-430, 500 The model DUPLEX-500 has a horizontal flue outlet (instead of vertical as for the other models), the outlet is in the right side of the boiler (seen the boiler from the control panel).

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4.2 HEAT EXCHANGER The DUPLEX boiler heat exchanger consists of multiple vertical water tubes, laser welded to upper and lower water collectors, and is fabricated from E24/2 and 30/10 carbon steel. The combustion chamber is located in the centre of the water tubes creating a totally water cooled chamber to ensure low boiler house floor temperatures. The number of the tubes which comprise the heat exchanger depends on the power of the boiler. The heat exchanger is silicone encapsulated, and is further insulated with foil backed mineral fibre wool, which maintains operational and standby losses at less than 1% of output. In the manufactering process three checking tests are made : verifying liquids, air pressure, water pressure. 1. Upper water collector 2. Lower water collector 3. Tubes of the heat exchanger 4. Tubes of combustion chamber 5. Combustion chamber 6. Burner 7. Flue collector 8. Fan motor 9. Water return 10. Water flow 11. Flame 12. Flue (burnt gases) 13. Flange to fit chimney 14. Boiler casing

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4.3 BURNER 4.3.1 Kit pilot burner and control flame The kit has the following parts : - Rectification electrode - Ignition electrode - pilot burner Ignition is provided by fully automatic HT spark to an intermittent atmospheric pilot burner. Flame proving is via a rectification system. This detects initially the presence of the pilot flame, and then establishes that the main burner flame is alight. Once the main burner flame is stable, the pilot flame is shut off. The pilot burner has only one gas injector 4.3.2 Main burner The main burner :

A. Gas collector B. Threaded brass injectors C. Ignition electrode D. Rectification electrode E. Pilot Burner F. Burner line assembly G. Elbow for pilot burner H. Air damper motor I. Pilot burner adjusting combustion

Burner lines - number depending on the power of the boiler. The useful potential of each line is 68 kW. Due to the design of the burner :

- The flame is distributed all along the surface of the main burner. - The mix air-gas inside the burner is cooling the burner.

MODEL

U.

220

290

360

430

500

Burner Lines # 3

4

5

6

7

Main Burner

Gas Jets

#

24

32

40

48

56

15

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4.4 GAS CONNECTION Listed below are the components of the natural gas train included in the DUPLEX boilers. For Propane gas (LPG) the parts (1) and (2) are not included. (1) Boiler gas governor (8) Hole plate for the air damper (2) Gas governor knob (9) Threaded arm link (3) DUNGS multiblock gas valve (10) Air damper (4) Multiblock gas valve knob (11) Air collector (air damper casing) (5) Electrical connections (12) Minimum gas pressure switch (6) Gas butterfly valve (13) Maximum gas pressure switch (7) Gas collector (14) Pilot burner valve

(15) Gas flow fine adjust screw

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The diameter of the gas supply pipe to individual boilers will vary according to the power of the boiler and the type of gas used.

Gas connection diameter

DUPLEX model

Heat Output

kW Natural Gas

Propane Gas

DUPLEX-220

204

1 1/4"

1"

DUPLEX-290

275

1 1/2"

1 1/4"

DUPLEX-360

340

1 1/2"

1 1/4"

DUPLEX-430

408

1 1/2"

1 1/4"

DUPLEX-500

472

2"

1 1/4"

Natural Gas, G20 (20 mbar); Low calorific value (at 150C and 1013 mbar)= 34.02 MJ/m3 Propane Gas, G31 (37 mbar); Low calorific value (at 150C and 1013 mbar)= 88 MJ/m3 4.5 CONTROL PANEL Each Duplex boiler is supplied with a factory fitted and fully tested control panel which comprises:- double pole isolator, burner flame safeguard control box with illuminated lockout reset button, control thermostat, manual reset high limit safety thermostat, revolving drum type flow and return thermometers, hours run counter and high fire delay timer. Also provided are status indicator lamps to indicate burner enabled, burner firing, low gas inlet pressure and water overheat trip.

4.6 BOILER FLUEWAY SYSTEM The entrance of the air is placed at the back of the boiler, (A). In the Air Damper Casing, (B), the air is mixed with the gas. The mix burns in the main burner (C). The burnt gases, due to the negative pressure created by the motor-fan (H,G,F), go

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through the tubes of the heat exchanger, and are collected in the Flue Collector (D), and are driven to the chimney fitting flange (K). Then, the natural draught of the chimney must evacuate the burnt gases. The flueway system consist of : (A) New air entrance (B) Air damper (C) Combustion chamber (D) Flue Collector (E) Flue damper (F) Turbine casing (G) Turbine (H) Motor (I) Electrical condensor (J) Chimney fitting flange (K) Burnt gases Output 4.7 POSITION OF THE VARIOUS COMPONENTS Diagram To Follow

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4.8 TECHNICAL DETAILS

MODEL

U.

220

290

360

430

500

kW

122

165

208

245

283

Low Fire

Btu/h.

417,628

563,000

709,700

836,000

965,600

kW

204

275

340

408

472

Heat Output to Water

High Fire Btu/h.

696,048

938,300

1,160,080

1,392,096

1,610,464

kW

242.8

327.4

404.8

485.7

561.9

Heat Input

Gross High Fire Btu/h.

828,433

1,117,000

1,381,000

1,657,200

1,917,200

Flow temperature Max.

0C

90

90

90

90

90

Return temperature Min.

0C

55

55

55

55

55

liters

61

72

88

91

98

Water content

UK Gal

13.41

15.83

19.35

20

21.55

Min. ∆T=80C

l/sec

6.07

8.18

10.11

12.14

14.04

Water Flow

Rate Max ∆T=120C

l/sec

4.04

5.45

6.74

8.09

9.36

Maximum

Bar

4.85

4.85

4.85

4.85

4.85

Operating Pressure

Min.

Bar

1

1

1

1

1

m3/h

22.78

30.63

37.79

45.27

52.31

Natural Gas Input Rate

ft3/h

804.3

1081.4

1334.2

1598.3

1846.9

Nominal

mbar

20

20

20

20

20 Natural Gas

Inlet Gas Pressure

Min. - Max.

mbar

17 - 25

17 - 25

17 - 25

17 - 25

17 - 25

Volume (hot)

m3/h

341

462

566

676

785

Approx. Flue Natural Gas

Temperature

0C

121

121

121

121

121

Gas connection size (N.G.) BSP-F

1 1/4"

1 1/2"

1 1/2"

1 1/2"

2"

Flow/Return Connection

BSP-M

2 1/2"

2 1/2"

2 1/2"

2 1/2"

2 1/2"

Flue connection flange Diam.

mm

250

300

300

300

350

Flue system draught at boiler

mbar

0

0

0

0

0

Load

W

400

600

600

600

750

Electrical

Supply

V

220 / 240V, 50 Hz, Single Phase, earthed

kg

205

250

300

320

350

Weight Empty

lbs

451

551

661

705

771

kg

266

322

388

411

448

Weight Full

lbs

585

709

855

906

987

Lower Calorific Value NATURAL GAS, G20 (150C, 1013 mbar) = 34,02 MJ/m3

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4.9 DIMENSIONAL DATA

MODEL

220

290

360

430

500

A

522

522

669

669

669

B

520

520

715

715

715

C

490

535

450

470

560

D (Flue, Chimney flange)

250

300

300

300

350

E

152

152

180

180

180

F

180

180

230

260

220

G (Water connections)

2 1/2"

2 1/2"

2 1/2"

2 1/2"

2 1/2"

Natural Gas

1 1/4"

1 1/2"

1 1/2"

1 1/2"

2"

H (Gas connection)

Propane Gas

1"

1 1/4"

1 1/4"

1 1/4"

1 1/4"

I

410

410

410

410

455

J

159

169

169

169

184

K

152

192

192

192

215

L

402

402

477

477

196

M

110

110

183

183

473

N

36

75

15

33

72

P

180

222

162

186

245

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4.10 ELECTRICAL DETAILS 4.10.1 SATRONIC control system Circuit diagram and illustration of mode of operation HS Main Switch GW1 Min. Gas pressure switch GW2 Max. Gas pressure switch ST Safety Limit Thermostat RT Control thermostat IS Ionizer Z Ignition transformer M Motor fan V1 Safety electro-valve V2 Main burner electro-valve PV Pilot gas valve LW Air Pressure Switch SA Burner lockout signal tw Start-up time tv1 Pre-ventilation time tvz Pre-ignition time ts1 Safety time ionisation pilot burner ts2 Safety time ionisation burners tv2 Delay time for high fire Circuit Diagram : On one side of the control unit there is a multi-coloured disk which shows, at all times, the point reached in the operating cycle of the boiler. This disk, in conjunction with the control panel indicators, allows us to define at what stage the operating cycle a fault has arisen, and locate the origin of the fault.

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4.10.2 Electrical wiring diagram for DUPLEX boiler, models 220-290-360-430

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4.10.3 Electrical wiring diagram for DUPLEX boiler, model 500

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4.11 MANUFACTURING BOILER LABEL

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SECTION FIVE INSTALLATION 5.1 THE BOILER ROOM The boiler room must be clean , well ventilated, well lit and constructed in accordance with the requirements of BS6644. The safety standard of the room must satisfy the conditions set out in BS5588:Part 1. Above all, this room must not serve as a storage area. All components of the boiler must be accessible, to permit the necessary maintenance operations. 5.2 AIR SUPPLY & VENTILATION An adequate supply of fresh air for combustion and ventilation of the boilerhouse must be supplied in accordance with BS6644. The air supply should be achieved using : a) Natural ventilation with low level and high level openings. b) Using a fan to supply air to a low level opening with natural discharge through a high level opening. c) Using a fan to supply air to a low level opening and a fan to extract air at a high level opening. 5.2.1 Air supply by natural ventilation Where natural ventilation is used, suitable permanent openings, at high level and at low level, connected directly to the outside air must be provided. Where communications with the outside air is possible only by means of high level air vents ducting down to floor level for the lower vent(s) should be used. For an exposed boilerhouse, air vents should be fitted, preferably on all four sides, but at least on two sides. The openings should have negligible resistance and must not be sited in any position where they are likely to be easily blocked or flooded or in any position adjacent to an extraction system which is carrying inflammable vapour. Grilles should be so designed that high velocity air streams do not occur within the space housing the boilers. The total minimum free area requirements of the air vents should be as follows (boilers installations up to 2 MW), (these requirements are related to the maximum rated heat input of the boiler(s) and are equivalent to those specified in BS6644) : Position of air vent

Free areas (air direct from outside)

High level (outlet)

270cm2 plus 2.25cm2 per kW in excess of 60 kW of total rated input

Low Level (inlet)

540cm2 plus 4.5cm2 per kW in excess of 60 kW of total rated input

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The actual minimum effective areas of the air vents required are as follows :

Free Area of Vent per boiler model (air direct from outside)

Air Vent

Uts.

Duplex-220

Duplex-290

Duplex-360

Duplex-430

Duplex-500

cm2/boiler

681.5

872

1046

1228

1399.5

High

in2/boiler

106

135.5

162.5

190.5

217

cm2/boiler

1363

1744

2092

2456

2799

Low

in2/boiler

212

271

325

381

434

5.2.2 Air Supply by mechanical ventilation Mechanical ventilation systems serving the area containing the boiler should be designed with an extraction air rate of 0.45 m3/sec per 1000 kW total rated input, and an inlet air rate of 1.1 m3/sec per 1000 kW total rated heat input. Systems employing an extract fan only must not be used, whereas the use of a single inlet fan, or an inlet together with an extract fan, is acceptable. All air inlet and extract fans should be electrically interlocked to cause safety shut-down or lock-out of the boiler in the event of malfunction of either fan. The requirements of mechanical ventilation schemes is fully outlined in BS6644. The following table gives the minimum mechanical ventilation rates of the DUPLEX range of boilers : AIR

Uts.

Duplex-220

Duplex-290

Duplex-360

Duplex-430

Duplex-500

Inlet (combustion, ventilation)

m3/s

0.267

0.36

0.445

0.534

0.618

Extract (ventilation)

m3/s

.0133

0.18

0.222

0.267

0.309

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5.3 BOILER BASE Duplex boilers/modules should be installed on a level fire-proof plinth with a minimum height of 50mm. The plinth must be capable of supporting the weight of the boilers/modules when they are filled with water. 5.4 MODULAR CONNECTION Where the required boiler output exceeds the output of a single boiler, a multiple or modular arrangement of DUPLEX boilers should be considered. All DUPLEX boilers should be installed in accordance with the relevant requirements of the Building Regulations, Health and Safety Executive Regulation PM5, IEE Regulation and the Byelaws of the local authority and local water company. CODES OF PRACTICE CP341.300-307 Central Heating by low pressure hot water. CP342 Part 2. Centralised hot water supply CIBSE Guide Reference Sections B7, B11 and B13 BS6644 Installation of gas fired hot water boilers rated inputs above 60 kW but

not greater than 2 MW. IG/UP/2 Gas installation pipework, boosters and compressors on industrial and

commercial premises. 5.5 ELECTRICAL CONNECTION The electrical installation must comply with the current edition of the IEE Regulations. The supply voltage must be 220/240 V, ac, 50 Hz, single phase, earthed. Electrical loading : Boiler model 220 = 400 W

Boiler model 290, 360, 430 = 600 W Boiler model 500 = 750 W

The boiler must be earthed. Electrical connections are made to the main terminal rail in the boiler control panel. The connections should be as follows :

- Supply live to terminal 2 - Supply neutral to terminal 1 - External controls require to be volt free switched - Low fire (stage 1) terminals 3 and 4 - High fire (stage 2) terminals 5 and 6

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5.6 MOUNTING THE BOILER The dimensions and weight of the DUPLEX boilers generally do not restrict the sitting position. The minimum clearances detailed below should be observed.

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5.7 SYSTEM WATER The DUPLEX boiler has a very high coefficient of heat transfer and, like all boilers of its type, has a strict requirement for certain system design considerations as well as water quality/system waterside cleanliness. The following points MUST be observed : a. The DUPLEX boiler must only be installed into a sealed and pressurised system.

Open vented systems are not suitable. b. Systems must be thoroughly cleansed before connecting the boiler. c. Where the entire system into which the boiler is to be installed is new, the water quality

must be in accordance with the requirements listed below. d. Where the boiler is to be retrofitted into an existing system, (a very aged heating

system where damaging system sludge, debris, magnetite sludge may be often be found in large quantities in an old system) the boiler must be separated from the old parts of the system by a plate exchanger to avoid the appliance from being contaminated and damaged by ferric oxide sludge that will be present in the old system.

Where a new DUPLEX boiler is installed in conjunction with a plate heat exchanger, the water in the primary (boiler) side of the plate heat exchanger need only be treated with a good quality corrosion inhibitor. In addition, as the primary system will be confined to just the plantroom, automatic makeup is not considered necessary.

e. No guarantee will be allowed on the boiler unless the above requirements (as

appropiate installation are STRICTLY observed. 5.7.1 Cleansing of old systems Before installing any new boiler, a thorough cleansing of an old system is required to remove sludge and silt, ... The chemicals used must be compatible with the materials used in the system. 5.7.2 Cleansing of new systems New systems must be cleaned of all solid debris, traces of oil, flux residues, dirt, etc.

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5.7.3 Water quality The listed water quality requirements must be observed when the entire water content of the system is available to the boiler. Please note however, it is always good practise to water treat all systems. CONCEPT

DETAIL

VALUE

pH

between 8,5 and 10

Total hardness (TH)

lower than 60ppm

Turbidity (MES)

lower than 10 mg/l

Iron (mg/l)

lower than 1 mg/l

Resistivity

greater than 2.000 Ohm x cm

WATER PARAMETERS

Conductivity

lower than 500 µS/cm

5.8 WATER FLOW RATE AND TEMPERATURE RISE The DUPLEX boiler is designed to operate with a ∆T of between 8 - 12 0C. Pumps should be selected to overcome the boiler index circuit to provide a flow rate to achieve a ∆T within the required parameters outlined above. 5.9 OPERATING WATER TEMPERATURES

Maximum Flow Temperature

90 0C

OPERATING WATER

TEMPERATURES Minimun Return Temperature

55 0C

The DUPLEX boiler, in keeping with any carbon steel boiler must be protected from operation at low return temperatures. Measures must be taken to prevent the return temperature from remaining below 550C. 5.10 BOILER HYDRAULIC RESISTANCE The design of the boiler allows for very low pressure loss versus the power of the boiler and its physical size. The hydraulic pressure loss for a specific boiler can be found by reference to the graph below. Volume flow (Q) (m3/h) can be determined : Boiler Power (kW) x 0.86

Q= ------------------------------------- Design boiler T Maximum boiler ∆T = 120C Minimum boiler ∆T = 80C

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5.11 HYDRAULIC CONNECTIONS When fitting, the need for the following should be borne in mind : - Valves in the outflow and return pipes of each boiler. These valves allow the isolation

of the boiler and remove the need to drain the entire system in the event of an important maintenance operation being required.

- A safety valve between the boiler and the outflow valve and a drainage pipe between the boiler and the return valve.

- A mechanism to establish a minimum pressure in the system. - An air venting or purger installed in the outflow pipe. This become absolutely

imperative when the boiler is installed in the higher parts of a building. - An appropiate expansion system. - A drainable inertial tank depending on the volume of water and the power. 5.11.1 Inertial tank The DUPLEX boiler should always be installed in conjunction with an inertial tank unless the whole installation is :

a. Constant temperature - constant flow, or b. The system includes a constant temperature - constant flow circuit that is

always in operation. The inertial tank or both systems listed above (a,b) must have a water capacity equal to or greater than that given by the following formula : Capacity (litres) = ( Boiler Power Output x 0.774 ) - ( Boiler Water Content(litres)) Boiler

Duplex-220

Duplex-290

Duplex-360

Duplex-430

Duplex-500

Min. Inertial volume (litres)

97

141

175

225

267

5.12 SYSTEM SCHEMATICS LIST OF EQUIPMENTS 5.12.1 Typical single boiler installation 1. DUPLEX boiler 2. Non return valve 3. Boiler circulation pump 4. Strainer 5. Expansion Vessel 6. Safety valve and pressure meter 7. Inertial tank 8. Boilers regulation 9. Air venting 10. Mixing valve (Weather compensated variable temperature) 11. Primary pump

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5.12.2 Typical installation of a single boiler for DHW production or a very old system

12. Three ways valve for control the flow temperature of domestic hotwater service 13. Plate heat exchanger 14. Dosing point 15. DHWS secondary pump 16. DHWS storage vessel 17. Thermostat pumps 18. Pressure relief valve 19. Three was valve for control the flow temperature of the DHW to secondary 20. Return temperature thermostat 21. Secondary recirculation pump 22. Non vibration flange 23. Flow swith 24. DHWS recirculation pump 25. Heating system pump 26. Magnetic filter 27. Magnetic filter pump 5.12.3 Typical multipleinstallation (heating, DHW) 28. Water meter

5.12.4 Typical multiple installation, for DHW production, or a very old system, or a heating system operating at low temperatures

29. Chemical product dosifier 30. Water softener 31. Air venting 32. Adjudting water flow valve 33. Pressure switch 34. Pressure meter 35. Temperature meter A. HEATING FLOW B. HEATING RETURN C. COLD FEED D. DRAIN E. DOMESTIC SANITARY WATER FLOW F. DOMESTIC SANITARY WATER RETURN

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5.13 GAS SUPPLY The gas installation should be installed in accordance with the guidance given in IGE/UP/2 and British Gas Publication IM/16. Each boiler must be equipped with an inlet isolation valve and a union or flange between the isolation valve and the boiler that allow disconnection of the boiler. Do not use pipes smaller than the size of the boiler gas connection. It is important to ensure that the supply of gas is adequate for the power of the boiler(s) and that the inlet working pressure of the natural gas must be maintained within the limits detailed below : minimum = 17 mbar, maximum =25 mbar, nominal = 20 mbar The availability of an adequate gas supply or the suitability of an existing supply/metering equipment should be established by reference to the local gas undertaking before installation. 5.14 FLUE SYSTEM Detailed recommendations for the flue are given in BS6644 and British Gas IM/11. The area of the flue must not be less than the area of the boiler flue outlet. Flue components should be watertight. The flue systems must be designed to induce a zero draught at the boiler flue connection when cold. When installing multiple DUPLEX boilers to a common flue header, the header should incline by 3-5% towards the main chimney. The fitting flange between the boiler and chimney are : Boiler model

Duplex-220

Duplex-290

Duplex-360

Duplex-430

Duplex-500

Boiler flue diameter mm

250

300

300

300

350

Flue pipes and fittings should be constructed from stainless steel or acid resistant vitreous enamel lined cast iron. Chimneys should be lined with non-porous acid resistant material in accordance with BS5854, such as stainless steel flexible flue liner or similar. The internal diameter of the liner must not be less than the recommended flue pipe, and the number of joints should be kept to a minimum. Any joints between the flexible liner and the flue pipe from the boiler should be effected by means of a purpose adapter plate. Existing flues should be thoroughly swept before use and any register plates, restrictor plates or dampers should be removed. The flue outlet should be fitted with a wire mesh to protect against blockage. The terminal should not be sited adjacent to any opening window, air vent or other ventilation opening, and should be situated at least one metre above the roof surface. All should be in accordance with BS6644.

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5.14.1 Possible flue connection for boiler model DUPLEX-220 to DUPLEX-430 a. An elbow adaptor may be fitted for connecting the boilers to the flue system. Boiler

220

290 to 430

r (mm)

90

90

D (mm)

250

300

H (mm)

340

390

b. Flue outlet may be rotated, 45 or 90, as the drawings attached, to provide discharge to either right and left. 5.14.2 Flue Outlet model DUPLEX-500 The flue connection on the model 500 is horizontal - side facing. This boiler model should be fitted to the main chimney as shown in the drawing attached. When installing two DUPLEX model 500 together, you should order one boiler with the left hand flue outlet and another with the right hand discharge as viewed from the front of the boiler.

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SECTION SIX START UP AND CONTROL 6.1 PRE-START CHECKS The first start-up operation is a critical operation on which the future effectiveness and reliability of the system can depend. For this reason, the supplier or an approved engineer must carry out the operation. Before start-up, it must be ensured that : - The boiler has been installed in accordance with the manufacturers instructions. - The system is full of water and vented of air. - The static pressure in the system is between one and three bars. - The valves are open - The water circulation pump(s) function correctly. - The gas pressure conforms with that indicated on the boiler identification plate. - The gas supply is on and purged of air. - There are no gas leaks in the system. - The electrical connections are correct (L,N, voltage 220/240 V, 50 Hz, earthed) - Power supply is available. - The controls are set so as to require heat from the system. - The minimum gas pressure switch is set to 10 mbar (natural gas). - The maximum gas pressure switch is set to 25 mbar. - The air pressure switch is set within the range 0.6 - 1.2 mbar 6.2 MEASURE INSTRUMENTS To adjust the boiler settings various instruments are required : - A manometer to check the pressure drop in the combustion chamber. - A manometer to check the gas burner pressure. - A manometer to check the inlet working pressure of the gas supply. - A flue gas analyser to measure CO, CO2, O2 and NOx. - Thermometers to measure the water and flue gas temperatures. 6.3. PREVIOUS CHECKINGS ON THE BOILER

a. PILOT ASSEMBLY b. AIR DAMPER MOTOR c. LOW-HIGH DELAY TIMER d. FLUE DAMPER

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6.4 ADJUSTING PILOT BURNER 6.4.1 Checking the pilot burner

* The pilot assembly should be removed and the ignition electrode adjusted to 2mm from the inside surface of the pilot burner and 1 mm from the base of the burner (as shown in previously supplied drawings).

* The ionisation electrode should be adjusted to travel away from the burner to enable the 200mm long pilot flame to encase the probe whilst it is being pulled by the combustion fan.

* The return set of the ionisation probe should be placed a significant distance away from the pilot burner, 5cm, to prevent spark migration to the probe, assisted by the air movement created by the combustion fan.

* The updated pilot burner has 11-12 holes (diameter 3mm each one) in place of the 22-23 small or 4 large holes.

* The electrodes should be inspected for cracking of the ceramic where they pass through the retaining nuts.

* When you fit the pilot burner into the boiler, you must be sure that no extra air entrance should be between the joints. In order to avoid it, you may put some sealing (in example, silicon) to the base.

6.4.2 Checking the combustion of pilot burner 6.4.2.1 Switch on the boiler 6.4.2.2 Place the boiler thermostat at high value. 6.4.2.3 If boiler lockout is produced, reset the boiler again. 6.4.2.4 The pilot burner will fire, a strong and blue flame must involve totally the

rectification probe with no lockout. 6.4.2.5 Adjust the combustion of the pilot burner :

* Rectification current of the pilot assembly must be greater than 6 micro Ampers. * The earth wire ( which creates the circuit for the rectification current) should be attached directly to the pilot assembly securing bolt.

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* Adjustment on the primary aeration ring (see drawing, Nr. J) on the pilot assembly will modify the micro Amper reading. If the ring go down the air flow will increase, if the ring go up the air flow will decrease.

* The rectification reading can be taken with a higher degree of accuracy if the supply to the second solenoid within the Dungs gas valve is interrupted :

- This is achieved by dismantling the multi-wire connector that plugs into the DUNGS valve and disconnecting the brown wire Nr. 3

- The unit will pass to lockout once the unit tries to establish low fire.

- Re-connect and plug the multi-wire connector into the DUNGS valve.

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6.5 PRIMARY AIR DAMPER MOTOR

The damper motor is preset, however if a new unit is supplied and the old unit is not available, the initial settings should be as follows :

* When the damper is in the high fire position the injectors in the gas manifold should be in view, but not the gas manifold. When viewed from directly above the assembly.

When the damper is in this position the link to the gas butterfly valve should bring the gas butterfly to the horizontal (fully open).

* For natural gas : the linkage between the damper and the gas butterfly valve should be set with the ball and socket bolt on the air damper in the second from the end hole, and the gas butterfly valve third from the end.

* For LPG : the linkage between the damper and the gas butterfly valve should be set with the ball and socket bolt on the air damper in the second from the end hole, and the gas butterfly valve third from the end.

* When the damper is in the low fire position it should have a gap of between 5-8 mm from the blade to the damper housing.

* This setting is intended as a guide and fine adjustments can be made once the unit is operating.

6.6 LOW - HIGH FIRE DELAY TIMER

The low to high fire delay timer is set at the factory to 2 minutes. However this is found to be short for the U.K. climate, a setting between 4 to 7 minutes would be suitable.

6.7 FLUE DAMPER The flue damper position is preset from factory. It is not usual to modify it. See explanation at 6.8.7a. It is function of the boiler size or model and the chimney. ( see 6.8.7a), Once this is adjusted for the draught, no more adjustings should be necessary during the operational life of the boiler. 6.8 ADJUSTMENT OF SECOND STAGE (HIGH FIRE) 6.8.1 Link boilers terminals 3 and 4 6.8.2 Link boilers terminals 5 and 6 6.8.3 Turn on the power supply and set the control thermostat to a high setting

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6.8.4 After a delay, the burner will function at high fire.

If the unit fails to operate from pilot to low fire, adjust the threaded linkage between the air damper and the gas butterfly valve to increase the through put at low fire.

Once high fire has been achieved the unit should be allowed to operate until the water flow temperature is is within 50C of the final working temperature.

6.8.5 Be sure the gas butterfly valve is at maximum opening (horizontal) 6.8.6 Ensure the throughput control on the DUNGS multiblock gas valve is set to maximum

opening. * Knob Nr. 4 (see drawing on Page Nr. 15) placed at maximum opening. * knob Nr. 15, max. opening ( Anticlockwise).

6.8.7a If a dedicated gas meter is not available the following steps must be taken

* Use the “Factory Settings Combustion Check List” (every boiler is delivered with his own “Checking List” from the factory) Attached to the inside of one of the top side panels.

* Verify the combustion chamber pressure (negative value) is near the setting from factory check list. Tolerance +/- 15%.

If pressure is too far from setting, adjust the flue damper (placed at back of the boiler).

If pressure is more negative --> close the flue damper. If pressure is less negative --> open the flue damper.

Once the damper has been adjusted, the locking nut should be tightened. No additional or future adjustments should be done to the flue damper.

* Check the manifold gas pressure (high fire) is near the setting from factory. Tolerances : +/- 15% from factory setting.

Adjust : burner pressure and combustion settings (CO2= 7.7 to 7.9%, for Natural Gas), by regulating the boiler gas governor at the rear of the unit, flue readings must be taken via the flue gas analyser.

* If you adjust the combustion settings :

- with the casing off, the CO2 will increase by approximately 0.2% when the casing is fitted.

- While boiler is working at a lower temperature than 700C, the CO2 will

increase when the boiler gets hotter.

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- 6.8.7b If a dedicated gas meter is available the following steps must be taken

* Adjust gas flow and combustion settings (CO2= 7.7 to 7.9%, for Natural Gas), by regulating the boiler gas governor at the rear of the unit, flue readings must be taken via the flue gas analyser.

- with the casing off, the CO2 will increase by approximately 0.2% when the casing is fitted.

- while boiler is working at a lower temperature than 700C, the CO2 will increase when the boiler gets hotter.

6.8.8 Once the unit is within 50C of the required flow temperature an accurate check can be

made. 6.9. ADJUSTMENT OF FIRST STAGE (LOW FIRE) 6.9.1 Turn off power supply and remove link between terminals 5 and 6. 6.9.2 Turn on power supply and the boiler should fire at low fire. 6.9.3 The adjustment for low fire is undertaken via the threaded link between the primary air

damper and the gas butterfly valve.

* Unscrew the locking of the threaded link.

* Turn the threaded link in the proper sense in order to obtain the combustion settings. You are adjusting the gas flow for a fixed air flow.

On low fire, the CO2 (%) value maybe 0.2 % lower than for high fire, but inside 7.7% to 7.9%.

* Once a suitable figure has been achieved the linkage should be locked with the two locking nuts one at either end.

* Check the Gas Jets Pressure and the Combustion Chamber Pressure (both negatives) are near to the values of the factory settings.

6.9.4 Only if necessary : Adjust burner air damper position (only if last values checked are

very different from factory settings).>15%+

* With the boiler switched on.

* For increasing the air flow, on the air damper motor you must link between terminals Nr. 2 and 3.

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Once the combustion readings (in the flue gas analyser) are reached (CO2 = 7.7% to 7.9%), switch off the boiler.

The air damper will remain at the last position.

* Lock the minimum opening position for the air damper by means of the locking included in the motor.

* Check the Gas Jets Pressure and the Combustion Chamber Pressure (both negative) are near to the values of the factory settings.

6.10 WARNINGS ON COMBUSTION HIGH AND LOW FIRE : 6.10.1 If the unit is allowed to run with a CO2 reading greater than 8,2% (with the

casing in place) the burner will fail due to overheating. 6.10.2 The boilers must not be operated if work is being undertaken within the vacinity

of the plant that will create airbourne dust. 6.10.3 When several boilers are installed in the same boiler room, the gas dynamic

pressure (when all the boilers are operating at high fire at the same time) must be checked. The dynamic pressure must be greater than 18 mbar.

6.10.4 Combustion adjust for L.P.G. (Propane, G31) boiler :

* The boilers supplied for burning with L.P.G. will not have a gas governor.

* The gas flow adjustment is made by means of the knobt (Nr. 15, see drawing in Page Nr. 15) of the DUNGS gas valve. Turning it in a clockwise direction will decrease the gas pressure, anticlockwise turning will increase the gas pressure.

* Combustion figures should be CO2 between 7.7 and 7.9 % (high fire).

6.11 READINGS ON THE BOILER

Here is attached a drawing with the reading points for the several values requested for adjusting the DUPLEX boilers.

1. O2% value 2. CO2% value 3. CO(ppm) value 4. Air excess 5. Boiler efficiency (%) 6. Flue temperature (0C) 7. Flow water temperature (0C) 8. Return water temperature (0C) 9. Boiler room temperature (0C) 10. Inlet Gas Pressure (mbar.)

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11. Burner Jets gas pressure (mbar.) 12. Gas consumption (m3/h) 13. Combustion chamber pressure (mbar.) 14. Flue collector pressure (mbar.) 15. Chimney pressure (mbar.)

42

NOTE : At the end of each first start-up operation, all the readings relating to combustion figures (combustion, air pressure, operating water temperatures, ...) should be taken. See table above :

Sample

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SECTION SEVEN FAULTS DURING OPERATION Should a fault occur, it will be necessary to contact a specialist engineer for assistance. There are predominantly two types of fault:

- those which lead to inefficient operation or combustion. - those which cause the boiler to stop working.

7.1 POOR COMBUSTION The poor combustion does not result in the boiler not working, but reduces the efficiency and effectiveness of the boiler. The usual indication of a problem in this area is noisy or unstable combustion and/or a yellow colouring of the flame. The usual course of action is to re-commission the boiler in accordance with the start-up instructions. 7.2 FAULTS THAT CAUSES THE BOILER NOT WORKING In order to ascertain the problem area or component which causes the boiler to stop working, it is necessary to observe the point at which the boiler operating sequence stops. The boiler is controlled by a Satronic flame safeguard control box. On one side of the control unit there is a multi-coloured disk which shows, at all times, the point reached in the cycle at a given instant. This apparatus, in conjunction with the control panel lights, allows us to determine at what stage the operating cycle a fault has arisen, identifying the problem area. 7.2.1 White Sector and the boiler is not operating. Check that : - there is a heat requirement. - the regulating thermostat electrically connected and calling for heat. - the control box, Satronic, is properly connected. 7.2.2 BLUE Sector. The boiler has stopped due to lockout of the control box, the green lamp indicating heat demand is lit. Check : - the volume control damper at the inlet to the combustion fan. - the fan motor connections and the condition of the fan. - the setting of the air pressure switch. 7.2.3 RED Sector. The boiler has stopped due to lockout of the control box, the green lamp indicating heat demand is lit. Check :

44

- the pilot burner gas supply solenoid coil. - the isolation of the ignition and rectification electrodes. - the spark gap between the ignition electrode and the pilot burner. - the ignition transformer. - the gas pressure switch for maximum is set properly. 7.2.4 YELLOW Sector The boiler has stopped due to lockout of the control box, the green lamp indicating heat demand is lit, the amber lamp indicating low gas pressure is lit, the red lamp indicating lockout is not lit. Check : - the gas supply pressure. - the gas valves solenoid coils. - the setting of the minimum gas pressure switch. 7.2.5 GREEN sector The boiler has stopped. The green lamp indicating indicating heat demand is lit. Check the boiler combustion. 7.2.6 GREEN sector. The boiler has stopped. The green lamp indicating indicating heat demand is lit, the red lamp indicating overheating is lit. Check : - the system is correctly filled, : the water pressure, water flow and the inertial volume. - the pumps are running - the calibration of the control thermostat. Note : it will be necessary to reset the safety limit thermostat with a screwdriver.

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FAULT

CAUSE

ACTION TO BE TAKEN

Boiler has stopped On-Off Switch not lit

- On-off switch is off. - No electrical supply to the boiler

- Press the On-off switch - Check the electrical supply.

Boiler has lockout Control box lamp is lit

It does not mean a fault in the boiler. Several external factors may be the cause

- Reset the boiler - Check installation and system.

Boiler has stopped Green lamp indicating heat demand is not lit.

- No heat demand in the system. - Control thermostat set very low - Water pressure switch detects no pressure - Boiler pumps are stopped. - External control no acts.

- Check the system water temperature - Set the control thermostat - Check the water pressure on the boiler circuit - Check the pump - Check external controls

Begin the boiler cycle and the boiler gets lockout.

- Burner is dirty - Air damper not proper set - Air pressure switch not correct. - Motor-fan does not operate.

- Clean the burner and check. - Increase air flow - Set pressure air switch to 0.6 mbar - Check pressure - Check motor-fan

No ignition spark Lockout light of control box is lit.

- Cracked ignition electrode ceramic - Gap between ignition electrode and pilot burner or earthed - Ignition transformer broken. - Control box broken

- Change ignition electrode - Set gap to 2 mm - Change transfomer - Change control box

When carrying out normal cycle, cuts out asap burner is lit.

- Cracked ionization electrode - Control box faulty - Gas Pressure Switch max. set too low

- Change ionization electrode - Change Control box - Set Pressure Switch Maximum

The burner fails to ignite

- No gas flow - Gas flow inadequate - Excess of air - Faulty/not supplied pilot solenoid valve - Faulty air damper motor. - Pilot burner fails to ignite - Burner in poor condition

- Check the gas valve is opened - Check gas pressure and flow - Decrease the air flow - Check electro-valve - Change air damper motor - Check pilot burner electro-valve - Check or change burner

Abnormal noises in the boiler heat exchanger

- Air inside the water piping - Pump running so fast - Scaling on inside the boiler - Sludge inside the exchanger

- Air vent the system - Adjust pump flow - Clean with descaling product - Check water quality / system leakages - Install water treatment - Clean the heat exchanger - Clean installation + filter before boiler

No lockout of Control box. All lamps not lit. On-off switch lit + Control thermostat lit

- Control thermostat faulty - External boilers controls

- Check and change if required - Check, link the boilers terminals 3 & 4, to operate the boiler.

No lockout of Control box. All lamps not lit. Control thermostat lit Red Lamp is lit

- Control thermostat faulty - System inertial due to high temp. - Low inertial water volume in boiler - Boiler pump failure - Water valves are closed.

- Replace thermostat. - Reset boiler. - Check inertial volume. - Check mixing valves - Check boiler pump - Check boiler water valves

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SECTION EIGHT MAINTENANCE 8.1 CLEANING THE BURNER AND THE COMBUSTION CHAMBER - You must clean the burner each 1000 hours measured in the hours run counter of the boiler, it depends also of the dust in the air of the boiler room. - Turn off the gas - Switch off the power - Remove the top and upper side casing panels - Disconnect the HT and rectification connections from the electrodes - Disconnect the wiring of the air damper motor - Separate the burner from the gas supply by removing the four screws in the flange on the outlet of the Dungs gas valve. - Unscrew the retaining nuts to free the burner - Dismantle all the copper piping connected to the pilot - Take out the air distributor and the burner - Separate the burning mounting from the air collector - Clean the mounting inside and out with a brush or pressurised air. - Dismantle the electrodes and check the state of the ceramic, adjusting the ignition electrode to 2 mm of the inner part of the pilot burner, adjust the position of the rectification electrode. - Clean the combustion chamber using a brush and vacuum cleaner - Reassemble by reversing the procedure 8.2 CLEANING THE HEAT EXCHANGER - Dismantle the casing - Remove the thermal insulation - Remove the burner - Dismount the combustion fan assembly - Clean the inside of the combustion chamber with an industrial vacuum cleaner - Clean the smoke passages with an industrial vacuum cleaner with brushes - Check soundness of combustion chamber silicone sealing, and if necessary make local repairs. 8.3 CHECKING BOILER - Start up the boiler system - Check the ignition spark. 2 mm separation - Check the pilot flame - Check the burner flame verifying that the combustion levels correspond to the type of gas being used; carry out the checks at low and high fire.

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SECTION NINE LIST OF BOILERS COMPONENTS