baxi Instant 105e User guide

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Baxi Combi Instant 80e & 105e

Gas Fired Wall Mounted Combination

Boiler

Installation & Servicing Instructions

Please leave these instructions with the user

Natural Gas

Baxi Combi Instant 80e

G.C.No47 075 13

Baxi Combi Instant 105e

G.C.No47 075 09

The boiler meets the requirements of Statutory Instrument “ The Boiler (Efficiency) Regulations 1993 N

3083” and is deemed to meet the requirements of Directive 92/42/EEC on the energy efficiency requirements for new hot water boilers fired with liquid or gaseous fuels:-

Type test for purpose of Regulation 5 certified by: Notified Body 0051.

Product/Production certified by: Notified Body 0051.

For GB/IE only.

Baxi is one of the leading manufacturers of domestic

heating products in the UK.

Our first priority is to give a high quality service to our

customers. Quality is designed into every Baxi product

- products which fulfil the demands and needs of

customers, offering choice, efficiency and reliability.

To keep ahead of changing trends, we have made a

commitment to develop new ideas using the

latest technology - with the aim of continuing to

make the products that customers want to buy.

Everyone who works at Baxi has a commitment to

quality because we know that satisfied customers

mean continued success.

We hope you get a satisfactory service from Baxi. If

not, please let us know.

Baxi is a BS-EN ISO 9001

Accredited Company

1.0 Introduction 5

2.0 General Layout 6

3.0 Appliance Operation 7

4.0 Technical Data 9

5.0 Dimensions and Fixings 11

6.0 System Details 12

7.0 Site Requirements 15

8.0 Installation 20

9.0 Commissioning the Boiler 25

10.0 Completion 27

11.0 Servicing the Boiler 28

12.0 Changing Components 30

13.0 Illustrated Wiring Diagram 39

14.0 Fault Finding 40

15.0 Short Parts List 47

Section Page

Contents

Legislation

Codes of Practice, most recent version should be used

IMPORTANT - Installation, Commissioning, Service & Repair

This appliance must be installed in accordance with the manufacturer’s instructions and the regulations in force. Read the instructions fully before installing or using the appliance.

In GB, this must be carried out by a competent person as stated in the Gas Safety (Installation & Use) Regulations.

Definition of competence: A person who works for a CORGI registered company and holding current certificates in the relevant ACS modules, or valid ACoP equivalents, is deemed competent.

In IE, this must be carried out by a competent person as stated in I.S. 813 “Domestic Gas Installations”.

This product should be lifted and handled by two people. Stooping should be avoided and protective equipment worn where necessary. Carrying & lifting equipment should be used as required.

The addition of anything that may interfere with the normal operation of the appliance without express written permission from the manufacturer or his agent could invalidate the appliance warranty. In GB this could also infringe the Gas Safety (Installation and Use) Regulations.

Warning - Check the information on the data plate is compatible with local supply conditions.

“Benchmark” Log Book

As part of the industry-wide “Benchmark” initiative all Baxi boilers now include an Installation, Commissioning and Service Record Log Book. Please read the Log Book carefully and complete all sections relevant to the appliance and installation. These include sections on the type of controls employed, flushing the system, burner operating pressure etc. The details of the Log Book will be required in the event of any warranty work. Also, there is a section to be completed at each subsequent regular service visit. The Log Book must be left with the user.

All CORGI registered installers carry a CORGI identification card and have a registration number. Both should be recorded in your boiler Log Book. You can check your installer is registered by telephoning +44 (0)1256 372300 or writing to:-

1 Elmwood,

Chineham Business Park,

Crockford Lane,

Basingstoke. RG24 8WG

Baxi declare that no substances harmful to health are contained in the appliance or used during appliance manufacture.

The appliance is suitable only for installation in GB and IE and should be installed in accordance with the rules in force, and only used in a suitably ventilated location.

In GB, the installation must be carried out by a CORGI Registered Installer. It must be carried out in accordance with the relevant requirements of the:

• Gas Safety (Installation & Use) Regulations.

• The appropriate Building Regulations either The

Building Regulations, The Building Regulations (Scotland), Building Regulations (Northern Ireland).

• The Water Fittings Regulations or Water Byelaws in Scotland.

• The Current I.E.E. Wiring Regulations.

Where no specific instructions are given, reference should be made to the relevant British Standard Code of Practice.

In IE, the installation must be carried out by a competent Person and installed in accordance with the current edition of I.S. 813 ‘Domestic Gas Installations’, the current Building Regulations and reference should be made to the current ETCI rules for electrical installation.

All systems must be thoroughly flushed and treated with inhibitor (see section 6.2).

In GB the following Codes of Practice apply: Standard Scope

BS 6891 Gas Installation. BS 5546 Installation of hot water supplies for

domestic purposes. BS 5449 Forced circulation hot water systems. BS 6798 Installation of gas fired hot water boilers. BS 5440 Part 1 Flues. BS 5440 Part 2 Ventilation. BS 7074 Expansion vessels and ancillary equipment

for sealed water systems. BS 7593 Treatment of water in domestic hot water

central heating systems.

In IE the following Codes of Practice apply: Standard Scope

I.S. 813 Domestic Gas Installations. The following BS standards give valuable additional information; BS 5546 Installation of hot water supplies for

domestic purposes. BS 5449 Forced circulation hot water systems. BS 7074 Expansion vessels and ancillary equipment

for sealed water systems. BS 7593 Treatment of water in domestic hot water

central heating systems.

1.0 Introduction

1.1 Description

1. The Baxi Combi Instant 80e or 105e is a fully automatic gas fired wall mounted combination boiler. It is room sealed and fan assisted, and will serve central heating and mains fed domestic hot water.

2.The unit incorporates a small storage cylinder built into the boiler providing hot water the moment the tap is turned on.

3. The boiler is set to give a maximum output of 24.0 kW (Instant 80e) or 31.0 kW (Instant 105e).

4. It is designed for use on Natural Gas (G20) and can be converted to use Propane (Instant 80e and 105e) or Butane (Instant 80e only).

5. The boiler is suitable for use only on fully pumped sealed heating systems. Priority is given to domestic hot water.

6. The boiler data badge gives details of the model, serial number and Gas Council number and is situated on the control box. It is visible when the case front panel is removed (Fig. 1).

7. The boiler is intended to be installed in residential / commercial / light industrial E.M.C. environments on a governed meter supply only.

8. The boiler must be installed with one of the purpose designed flues such as the standard horizontal flue kit, part no. 247719.

9. All systems must be thoroughly flushed and

treated with inhibitor (see section 6.2).

1.2 Instant Domestic Hot Water

(Expansion Vessel & Pre-Heat Store)

1. The boiler expansion vessel incorporates a small volume of stored primary hot water.

2. When the boiler has been off and there is then a demand for domestic hot water the stored primary hot water ensures that domestic hot water is supplied instantly at temperature.

3. The stored hot water is part of the primary circuit. This is not supplied as domestic hot water, which is fresh mains water heated by a heat exchanger within the boiler.

4. The stored primary hot water temperature is maintained whilst the boiler is in operation. During a period when there is no demand for heating or hot water the temperature of the stored primary hot water will eventually fall. The boiler will operate occasionally in order to maintain the temperature. This is indicated by the domestic hot water mode neon flashing.

1.3 Optional Extras

Various flue extensions, bends, vertical flue kits,control accessories etc. are availble as optional extras. These are detailed in a separate publication.

Data Badge

Fig. 1

Control Box

Case Front Panel

2.0 General Layout

2.1 Layout

1. Air Pressure Switch

2. Expansion Vessel & Pre-Heat Store

3. Burner Manifold

4. Automatic Air Vent

5. DHW Plate Heat Exchanger

6. Circulation Pump

7. Drain Off Point

8. Pressure Relief Valve

9. Position for Optional Integral Timer

10. Central Heating System Pressure Gauge

11. PCB

12. Control Box

13. 3-Way Valve Assembly

14. Spark Generator

15. Flame Sensing Electrode

16. Spark Electrode

17. Burner

18. Primary Heat Exchanger

19. Fan Assembly

20. On/Off/Reset Selector Switch

21. Central Heating Temperature Control

22. Domestic Hot Water Pre-Heat Control

23. Flame Failure

24. Safety Thermostat

25. Fault on Fan or Flue

26. Fault on Pump or Low System Pressure

27. Fault on Hot Water Sensor

28. Fault on Central Heating Sensor

29. Power On

30. Domestic Hot Water Mode

31. Central Heating Mode

32. Burner On

When neons 23 to 28 are constantly illuminated, they indicate the temperature of the central heating water.

30° 40° 50° 60° 70° 80°

bar

OFF

PREHEAT

30° 40° 50° 60° 70° 80°

23 24

26 27

30 31 32

3.0 Appliance Operation

NOTE: All delay timers mentioned in 3.1 and 3.2

are overridden by domestic hot water demand.

3.1 Central Heating Mode (Fig. 2)

1. With a demand for heating, the pump circulates water through the primary circuit. At a predetermined flow rate the central heating flow switch operates, initiating the ignition sequence.

2. The main burner ignites at low rate, then the gas valve controls the gas rate to maintain the heating temperature measured by the temperature sensor.

3. When the flow temperature exceeds the setting temperature, a 3 minute delay occurs before the burner relights automatically (anti-cycling). The pump continues to run during this period.

4. When the demand is satisfied the burner is extinguished and the pump continues to run for a period of 30 minutes (Pump Overrun).

5. If there is no other demand the pre-heat function will operate if switched on (see Section

3.2).

3.2 Domestic Hot Water - Preheat Mode

(Fig. 3)

1. With the pre-heat function switched on (preheat control fully clockwise), priority is given to the replenishment of the pre-heat store. The DHW mode neon ( ) will flash during this function.

2. The diverter valve remains in the DHW priority position. This allows the pump to circulate hot water to the store and back to the primary heat exchanger via the bypass pipe.

3. The automatic ignition sequence commences after approximately 25 seconds and the burner will light.

4. When the store reaches the desired temperature the burner is extinguished. The pump continues to run for a period of 30 seconds.

5. Following a demand for domestic hot water or the end of a central heating ON period, the preheat function restarts.

16 15 14 13 12

1 Primary Heat Exchanger 2 Burner 3 Ignition Electrode 4 Flame Sensing Electrode 5 Gas Valve 6Pump 7 Automatic Air Vent 8 Plate Heat Exchanger 9 Flow Sensor with Filter 10 Pressure Relief Valve 11 Boiler Drain Point 12 Heating Return 13 Cold Water Inlet On/Off Valve and Filter

14 Gas Inlet 15 Domestic Hot Water Outlet 16 Heating Flow 17 Pressure Gauge 18 Hydraulic Pressure Sensor Microswitch 19 Automatic By-Pass 20 Hydraulic Pressure Sensor 21 Diverter Valve Assembly 22 Domestic Hot Water Flow Priority Assembly 23 Domestic Hot Water Flow Priority Microswitch 24 Safety Thermostat 25 Central Heating Temperature Sensor 26 Expansion Vessel & Pre-Heat Store 27 Domestic Hot Water Temperature Sensor

Key

Central Heating Mode

Fig. 2

16 15 14 13 12

Domestic Hot Water - Preheat Mode

Fig. 3

3.0 Appliance Operation

3.3 Domestic Hot Water Mode (Fig. 3A)

1. Priority is given to the domestic hot water supply. A demand at a tap or shower will override any central heating requirement.

2. The flow of water will operate the DHW flow switch which requests the 3 way valve to change position. This will allow the pump to circulate the primary water through the DHW plate heat exchanger and take the stored water to give instant hot water.

3. The burner will light automatically and the temperature of the domestic hot water is controlled by the temperature sensor.

4. When the domestic hot water demand ceases the burner will extinguish and the diverter valve will remain in the domestic hot water mode, unless there is a demand for central heating.

5. If there is no other demand the pre-heat function will operate if switched on (see Section

3.2)

IMPORTANT: When the selector switch is in the ‘0’ (Off) position the electrical supply to the boiler is isolated. The boiler will not operate and the integral timer (if fitted) will require resetting once the selector switch is set to either Position (i) or Position (ii).

3.4 Frost Protection Mode

1. The frost protection mode is integral to the appliance and functions only with the selector switch (see Section 2.1) in the domestic hot water and central heating position. If the system temperature falls below 5° C then the boiler will fire on its minimum setting until a flow temperature of 30° C is reached. Further protection can be incorporated by using a system frost thermostat.

3.5 Pump Protection

1. With the selector switch (see Section 2.1) in either the central heating or central heating and hot water position the pump will automatically operate for 1 minute in every 24 hours to prevent sticking.

16 15 14 13 12

Key

Fig. 3A

Domestic Hot Water Mode

4.0 Technical Data

4.2 Combi Instant 80e

Flue Terminal Diameter 100mm Dimensions Projection 95mm

Outercase Dimensions

Casing Height - 780mm Overall Height Inc Flue Elbow - 980mm Casing Width - 450mm Casing Depth - 345mm

Clearances

Both Sides 5 mm Min Above Casing 200 mm Min Below Casing 200 mm Min Front 450 mm Min (For Servicing) Front 5 mm Min (In Operation)

Weights kg Packaged Boiler Carton 48.5 Packaged Flue Kit 3 Installation Lift Weight 42

Central Heating Primary Circuit Pressures

bar Safety Discharge 3 Max Operating 2.5 Min Operating 0.5 Recommend Operating 1-2

DHW Circuit bar Pressures

Max Operating 8 Min Operating 0.2

Min Operating Pressure at 12.7 l/min 0.96

Flow Rates l/min DHW Flow Rate @ 30o C Rise 13.7

DHW Flow Rate @ 35o C Rise 9.8

Min Working DHW Flow Rate 2.5

Pump - Grundfos UP 15-50

Available Head See graph below

Expansion Vessel - (For Central Heating only. Integral with appliance)

bar

Min Pre-charge Pressure 0.5

litre Max Capacity of CH System 80

Primary Water Content of Boiler (unpressurised) 3.0

Connections copper tails Gas Supply - 22mm Central Heating Flow - 22mm Central Heating Return - 22mm Cold Water Mains Inlet - 15mm DHW Flow - 15mm Pressure Relief Discharge - 15mm

Temperatures

C.H. Flow Temp (adjustable)

35°C to 85°C max (± 5°C)

D.H.W. Flow Temp

35°C to 65°C max (± 5°C) dependent upon flow rate 50°C Pre-heat OFF 65°C Pre-heat ON ± 5°C dependent upon flow rate

Heat Input C/H & DHW (Net)

Max Min

kW 26.3 10.6

Btu/h 89,739 36,168

Heat Output Max Min

kW 24.0 9.3

Btu/h 81,819 31,738

Electrical Supply 230V~ 50H

(Appliance must be connected to an earthed supply)

Power Consumption 170W

External Fuse Rating 3A

Internal Fuse Rating

Fuse 2A Fast Blow to BS 4265

Appliance Category CAT II

2H 3+

Max Gas Rate (Natural Gas - G20)

(After 10 Mins)

m3/h 2.78

ft3/h 98.12

Inlet Pressure (Natural Gas - G20)

mbar 20

in wg 8

Burner Injector (Natural Gas - G20)

12 x 1.28mm Diameter

Burner Pressure (Natural Gas - G20)

Max Rate Min Rate

mbar 12.2 ± 0.5 2.5 ± 0.2

in wg 4.88 ± 0.2 1.0 ± 0.2

Appliance Type C

NOxClass 3

Electrical Protection

IPX5D

This value is used in the UK Government’s Standard

Assessment Procedure (SAP) for energy rating of dwellings.

The test data from which it has been calculated have been

certified by 0051.

SEDBUK Declaration For Combi Instant 80e

The seasonal efficiency (SEDBUK) is 78.6 %

200 400 600 800 1000 1200

0.5

1.5

2.5

3.5

Metre wg

l/h

Pump - Available Head

4.5

5.5

LPG Gases Propane - G31 and

Butane - G30

Burner Injector

12 x 0.77mm diameter

Burner Pressure

Propane mbar

in wg

Butane mbar

in wg

Inlet Pressures

mbar in wg

Max Rate

36.2

14.5

28.3

11.3

Min Rate

6.4

2.6

5.3

2.1

Propane

14.8

Butane

11.2

4.0 Technical Data

4.2 Combi Instant 105e

Flue Terminal Diameter 100mm Dimensions Projection 95mm

Outercase Dimensions

Casing Height - 780mm Overall Height Inc Flue Elbow - 980mm Casing Width - 450mm Casing Depth - 345mm

Clearances

Both Sides 5 mm Min Above Casing 200 mm Min Below Casing 200 mm Min Front 450 mm Min (For Servicing) Front 5 mm Min (In Operation)

Weights kg Packaged Boiler Carton 50.5 Packaged Flue Kit 3 Installation Lift Weight 44

Central Heating Primary Circuit Pressures

bar Safety Discharge 3 Max Operating 2.5 Min Operating 0.5 Recommend Operating 1-2

DHW Circuit bar Pressures

Max Operating 8 Min Operating 0.2

Min Operating Pressure at 12.7 l/min 0.96

Flow Rates l/min DHW Flow Rate @ 30o C Rise 14.7

DHW Flow Rate @ 35o C Rise 12.7

Min Working DHW Flow Rate 2.5

Pump - Grundfos UP 15-60

Available Head See graph below

Expansion Vessel - (For Central Heating only. Integral with appliance)

bar

Min Pre-charge Pressure 0.5

litre Max Capacity of CH System 80

Primary Water Content of Boiler (unpressurised) 3.2

Connections copper tails Gas Supply - 22mm Central Heating Flow - 22mm Central Heating Return - 22mm Cold Water Mains Inlet - 15mm DHW Flow - 15mm Pressure Relief Discharge - 15mm

Temperatures

C.H. Flow Temp (adjustable)

35°C to 85°C max (± 5°C)

D.H.W. Flow Temp

35°C to 65°C max (± 5°C) dependent upon flow rate 50°C Pre-heat OFF 65°C Pre-heat ON ± 5°C dependent upon flow rate

Heat Input C/H & DHW (Net)

Max Min

kW 34.3 11.9

Btu/h 117,036 40,610

Heat Output Max Min

kW 31.0 10.4

Btu/h 105,776 35,490

Electrical Supply 230V~ 50H

(Appliance must be connected to an earthed supply)

Power Consumption 190W

External Fuse Rating 3A

Internal Fuse Rating

Fuse 2A Fast Blow to BS 4265

Appliance Category CAT II

2H 3P

Max Gas Rate (Natural Gas - G20)

(After 10 Mins)

m3/h 3.63

ft3/h 128.12

Inlet Pressure (Natural Gas - G20)

mbar 20

in wg 8

Burner Injector (Natural Gas - G20)

15 x 1.28mm Diameter

Burner Pressure (Natural Gas - G20)

Max Rate Min Rate

mbar 13.4 ± 0.5 1.8 ± 0.2

in wg 5.36 ± 0.2 0.72 ± 0.2

Appliance Type C

NOxClass 3

Electrical Protection

IPX5D

This value is used in the UK Government’s Standard

Assessment Procedure (SAP) for energy rating of dwellings.

The test data from which it has been calculated have been

certified by 0051.

SEDBUK Declaration For Combi Instant 105e

The seasonal efficiency (SEDBUK) is 78.5 %

200 400 600 800 1000 1200

0.5

1.5

2.5

3.5

Metre wg

l/h

Pump - Available Head

4.5

5.5

LPG Gases Propane - G31

Burner Injector

15 x 0.77mm diameter

Burner Pressure

Propane mbar

in wg

Inlet Pressures

mbar in wg

Max Rate

35.8 ±0.5

14.3 ±0.2

Min Rate

4.9 ±0.2 2 ±0.2

14.8

5.0 Dimensions and Fixings

Dimensions

A 780mm

B 345mm

C 450mm

D 107mm Ø Min.

E 200mm

F 190mm

G 143mm

360° Orientation

Tube Ø 100mm

Domestic Hot

Water Outlet

(15mm)

Cold Water

Inlet

(15mm)

Heating

Return

(22mm)

Heating

Flow

(22mm)

Pressure Relief

Valve

(15mm)

Gas

Inlet

(22mm)

65 mm

65 mm 65 mm

65 mm

Tap Rail

6.0 System Details

6.1 Information

1. The Baxi Combi Instant 80e and 105e Combination Boilers are ‘Water Byelaws Scheme - Approved Products’. To comply with the Water Byelaws your attention is drawn to the following installation requirements and notes (IRN).

a) IRN 001 - See text of entry for installation

requirements and notes. b) IRN 116 - Byelaw 90 and 91. c) IRN 302 - Byelaw 14.

2. Reference to the WRc publications, ‘Water fittings and materials directory’ and ‘Water supply byelaws guide’ give full details of byelaws and the IRNs.

6.2 Central Heating Circuit

1. The appliance is suitable for fully pumped SEALED SYSTEMS ONLY.

Treatment of Water Circulating Systems

• All recirculatory water systems will be subject to

corrosion unless an appropriate water treatment is applied. This means that the efficiency of the system will deteriorate as corrosion sludge accumulates within the system, risking damage to pump and valves, boiler noise and circulation problems.

• For optimum performance after installation this

boiler and its associated central heating system must be flushed. A means of achieving this is by following the guidelines given in BS 7593 “Treatment of water in domestic hot water central heating systems”.

• This must involve the use of a proprietary cleanser,

such as BetzDearborn Sentinel X300 or X400, or Fernox Superfloc. Full instructions are supplied with the products, but for immediate information please contact BetzDearborn (+44 (0)151 420 9563) or Fernox (+44 (0)1799 550 811) directly.

• For long term protection against corrosion and

scale, after flushing it is recommended that an inhibitor such as BetzDearborn Sentinel X100, or Fernox MB-1 or Copa used. The correct dosing is obtained by following the guidelines given in BS 7593.

Failure to flush and add inhibitor to the system may invalidate the appliance warranty.

• It is important to check the inhibitor concentration

after installation, system modification and at every service in accordance with the inhibitor manufacturer’s instructions. (Test kits are available from inhibitor stockists.)

• For information or advice regarding any of the

above contact the Baxi Helpline.

6.3 Bypass

1. The boiler is fitted with an automatic integral bypass.

6.4 System Control

1. The boiler is designed for use in a heating system that incorporates external controls, i.e. a minimum of a timer device.

2. Suitable timer kits are available as optional extras.

3. For optimum operating conditions and maximum economy the fitting of a programmable room thermostat, such as the Baxi Combi Controller, is recommended.

6.0 System Details

6.5 System Filling and Pressurising

1. A filling point connection on the central heating return pipework must be provided to facilitate initial filling and pressurising and also any subsequent water loss replacement/refilling.

2. There are connection points on the mains cold water inlet and central heating return isolating taps (Fig. 4a) to which the optional filling loop kit (Part No. 248221) can be assembled.

3. The filling method adopted must be in accordance with al relevant water supply regulations and use approved equipment.

4. Your attention is drawn to: for GB: Guidance G24.2 and recommendation R24.2 of Water Regulations Guide. for IE: the current edition of I.S. 813 “Domestic Gas Installations”.

5. The sealed primary circuits may be filled or replenished by means of a temporary connection between the circuit and a supply pipe, provided a ‘Listed’ double check valve or some other no less effective backflow prevention device is permanently connected at the inlet to the circuit and the temporary connection is removed after use.

6.6 Expansion Vessel

(Central Heating only)

1. The appliance expansion vessel is pre-charged to 0.5 bar. Therefore, the minimum cold fill pressure is 0.5 bar. The vessel is suitable for correct operation for system capacities up to 80 litres. For greater system capacities an additional expansion vessel must be fitted - refer to BS 7074 Pt 1.

6.7 Pressure Relief Valve (Fig. 5)

1. The pressure relief valve is set at 3 bar, therefore all pipework, fittings, etc. should be suitable for pressures in excess of 3 bar.

2. The pressure relief discharge pipe should be not less than 15mm dia, run continuously downward, and discharge outside the building, preferably over a drain. It should be routed in such a manner that no hazard occurs to occupants or causes damage to wiring or electrical components. The end of the pipe should terminate facing down and towards the wall.

3. The discharge must not be above a window, entrance or other public access. Consideration must be given to the possibility that boiling water/steam could discharge from the pipe.

Fig. 5

Stop Valve

Double Check Valve

DHW Mains Inlet

CH Return

Temporary Hose

Pressure Relief Valve

Filling Loop

Discharge Pipe

Fig. 4

Fig. 4A

Stop Valve

6.0 System Details

6.8 Domestic Hot Water Circuit (Fig. 6)

1. All DHW circuits, connections, fittings, etc. should be fully in accordance with relevant standards, the water supply regulations.

2. Your attention is drawn to: for GB: Guidance G17 to G24 and recommendation R17 to R24 of the Water Regulations Gude. for IE: the current edition of I.S. 813 “Domestic Gas Installations”.

3. A single check valve must be fitted as shown in Fig. 6 to prevent backflow to the supply pipe and to ensure the efficient operation of the expansion vessel which is required to accommodate the thermal expansion of the water.

4. When the domestic water system includes any device which prevents water expanding back towards the supply (check valve, loose jumpered stopcock, water meter, water treatment device), then an expansion vessel must be fitted (e.g. Zilmet 160ml, R

/215bar).

5. If the hot water expansion is not provided for, then high pressures can develop which may result in damage to fittings and devices on the system.

5. The boiler’s maximum working mains pressure is 8 bar, therefore all pipework, connections, fittings, etc. should be suitable for pressures in excess of 8 bar. A pressure reducing valve must be fitted for pressures in excess of 8 bar. The manufacturer of any outlet fittings, such as a shower valve, may require a lower maximum pressure. The pressure reduction must take account of all fittings connected to the DHW system.

6.9 Showers

1. If a shower control is supplied from the appliance it should be of the thermostatic or pressure balanced type. Thermostatic type shower valves provide the best comfort and guard against water at too high a temperature. Existing controls may not be suitable - refer to the shower valve manufacturer.

6.10 Hard Water Areas

1. If the area of the installation is recognised as a HARD WATER AREA then a suitable device should be fitted to treat the mains water supply to the boiler.

Boiler

Other Tap Outlets

Expansion Vessel

To Hot Taps

Check Valve

Pressure Reducer Valve

Stop Tap

Fig. 6

7.0 Site Requirements

7.1 Location

1. The boiler may be fitted to any suitable wall with the flue passing through an outside wall or roof and discharging to atmosphere in a position permitting satisfactory removal of combustion products and providing an adequate air supply. The boiler should be fitted within the building unless otherwise protected by a suitable enclosure i.e. garage or outhouse. (The boiler may be fitted inside a cupboard-see Section 7.3).

2. If the boiler is sited in an unheated enclosure then it is recommended to leave the ON/OFF Selector Switch in the domestic hot water and central heating position to give frost protection.

3. If the boiler is fitted in a room containing a bath or shower reference must be made to the relevant requirements. In GB this is the current I.E.E. Wiring Regulations and Building Regulations. In IE reference should be made to the current edition of I.S. 813 “Domestic Gas Installations” and the current ETCI rules.

4. If the boiler is to be fitted into a building of timber frame construction then reference must be made to the current edition of Institute of Gas Engineers Publication IGE/UP/7 (Gas Installations in Timber Framed Housing).

7.2 Clearances (Figs. 7 & 8)

1. A flat vertical area is required for the installation of the boiler.

2. These dimensions include the necessary clearances around the boiler for case removal, spanner access and air movement. Additional clearances may be required for the passage of pipes around local obstructions such as joists running parallel to the front face of the boiler.

200mm Min

780mm

450mm

200mm Min

5mm Min

450mm Min

For Servicing

Purposes

Fig. 7

Fig. 8

In Operation

7.0 Site Requirements

7.3 Ventilation of Compartments

1. Where the appliance is installed in a cupboard or compartment, no air vents are required as the appliance will run sufficiently cool without ventilation.

7.4 Gas Supply

1. The gas installation should be in accordance with the relevant standards. In GB this is BS 6891. In IE this is the current edition of I.S. 813 “Domestic Gas Installations”.

2. The connection to the appliance is a 22mm copper tail located at the rear of the gas service cock (Fig. 9).

3. Ensure that the pipework from the meter to the appliance is of adequate size. Do not use pipes

of a smaller diameter than the boiler gas connection (22mm).

7.5 Electrical Supply

1. External wiring must be correctly earthed, polarised and in accordance with the relevant regulations/rules. In GB this is the current I.E.E. Wiring Regulations. In IE reference should be made to the current edition of the ETCI rules.

2. The mains supply is 230V ~ 50Hzfused at 3A.

NOTE: The method of connection to the electricity supply must facilitate complete electrical isolation of the appliance.

Connection may be via a fused double-pole isolator with a contact separation of at least 3mm in all poles and servicing the boiler and system controls only.

Fig. 9

Gas Service Cock

7.0 Site Requirements

7.6 Flue

1. The following guidelines indicate the general requirements for siting flue terminals. For GB recommendations are given in BS 5440 Pt.1. For IE recommendations are given in the current edition of I.S. 813 “Domestic Gas Installations”.

2. If the terminal discharges onto a pathway or passageway, check that combustion products will not cause a nuisance and that the terminal will not obstruct the passageway.

3. If a terminal is less than 2 metres above a balcony, above ground or above a flat roof to which people have access, then a suitable terminal guard must be provided.

Terminal Position with Minimum Distance (Fig. 11) (mm)

A1Directly below an openable window, air vent or any other

ventilation opening. 300 B Below gutter, drain/soil pipe. 25 C Below eaves. 25 D Below a balcony/car port roof. 25 E From vertical drain pipes and soil pipes. 25 F From internal or external corners. 25 G Above adjacent ground or balcony level. 300 H From a surface facing a terminal. 600 I Facing a terminals. 1200 J From opening (door/window) in carport into dwelling. 1200 K Vertically from a terminal on the same wall. 1500 L Horizontally from a terminal on the same wall. 300 M1Above an opening, air brick, opening window etc. 300 N1Horizontally to an opening, air brick, opening window etc. 300

In addition, the terminal should be no nearer than 150mm to an opening in the building fabric formed for the purpose of accomodating a built-in element such as a window frame. See BS 5440 Pt. 1.

H,I

B,C

Likely flue positions requiring a flue terminal guard

Fig. 11

300 min

Terminal Assembly

Top View Rear Flue

Property Boundary Line

7.0 Site Requirements

7.7 Flue Dimensions

The standard horizontal flue kit allows for flue lengths between 100mm and 1m from elbow to terminal (Fig. 12).

The maximum permissible equivalent flue length is: Instant 80e 5 metres

Instant 105e 4 metres

NOTE: Each additional 45° of flue bend will

account for an equivalent flue length of 0.5m. eg. 45° = 0.5m, 90° = 2 x 45° = 1m etc.

7.8 Flue Terminal Trim

1. Once the flue is secure the trim can be fitted if required.

2. Remove the protective backing from the adhesive seal. Apply the seal to the rear of the trim flange (Fig. 13).

3. Locate the trim over the flue terminal and push it back to the wall to compress the seal (Fig. 14).

7.9 Terminal Guard (Fig. 15)

1. When codes of practice dictate the use of terminal guards, they can be obtained from most Plumbers’ and Builders’ Merchants.

2. There must be a clearance of at least 50mm between any part of the terminal and the guard.

3. When ordering a terminal guard, quote the appliance name and model number.

3. The flue terminal guard should be positioned centrally over the terminal and fixed as illustrated.

Fig. 12

Fig. 15

100mm

Fig. 14

Fig. 13

Flue Trim

Adhesive Seal

7.0 Site Requirements

7.10 Flue Options

1. The Baxi Combi Instant 80e and 105e can be fitted with flue systems as illustrated.

2. The standard flue Kit No 247719 is suitable only for horizontal applications.

3. Maximum permissible equivalent flue lengths are:-

Instant Instant 80e 105e

Concentric 5m 4m Vertical 4m 4m Vertical Two-Pipe 15m 12m

4. Any additional “in line” bends in the flue system must be taken into consideration. Their equivalent lengths are:-

Concentric Pipes:

45° bend 0.5 metres 90° bend 1.0 metres

Twin Flue Pipe

45° bend 0.25 metres 90° bend 0.50 metres

The elbow supplied with the standard horizontal flue is not included in any equivalent length calculations

5. The illustrations opposite show examples of maximum equivalent lengths.

6. Full details of part numbers and descriptions of all optional flue components and kits can be found in the Baxi Combination Boilers publication.

7. Instructions for guidance and fitting are included in each kit where appropriate.

Horizontal Flues

Vertical Flues

Vertical Flues (Twin Pipe)

Maximum Length = 3m inc. 2 x 45° bends

Maximum Length = 11m inc. 4 x 45° bends

Maximum Length = 2m inc. 2 x 90° bends

8.0 Installation

8.1 Initial Preparation

The gas supply, gas type and pressure must be checked for suitability before connection (see Section 7.4).

1. After considering the site requirements (see Section 7.0) position the fixing template (Fig. 16) on the wall ensuring it is level both horizontally and vertically.

2. Mark the position of the two most suitable fixing slots for the wall plate and boiler lower fixing holes. It is preferable to use the horizontal fixing slots.

3. Mark the position of the centre of the flue hole (rear exit). For side flue exit, mark as shown.

4. Note the shaded area on the template.

Pipework cannot be routed upwards behind the boiler.

5. If required, mark the position of the gas and water pipes. Remove the template.

6. Cut the hole for the flue (minimum diameter 107mm).

7. Drill the wall as previously marked to accept the wall plugs supplied. Secure the wall plate using the fixing screws.

8. Using a spirit level ensure that the plate is level before finally tightening the screws.

9. Connect the gas and water pipes to the valves on the wall plate using the copper tails supplied. Ensure that the sealing washers are fitted between the connections.

8.2 Flushing

1. Connect a tube to the central heating flow or return pipe (Fig. 17).

2. Flush thoroughly (see System Details, Section

6.2).

3. The use of the optional Baxi Filling Loop Kit (Part No. 248221) will simplify the flushing and soundness checking.

8.3 Preparing The Boiler

1. Remove all packaging.

2. Stand the boiler on its base by using the rear lower edge as a pivot.

NOTE: A small amount of water may drain from the boiler when the plastic caps are removed from the boiler connections.

Fig. 16

Fig. 17

Combi Instant

FIXING

TEMPLATE

5 mm Minimum Side Clearance

Horizontal Side Flue Centre Line

107mm Dia Minimum Aperture For Flue Tube

200 mm

Minimum

Clearance

200 mm

Minimum

Clearance

Profile of Outercase

Vertical Flue Centre Line

General Area For Electrical Supply

Hot Water

Outlet

(15mm)

Cold Water

Inlet

(15mm)

Heating

Return

(22mm)

Heating

Flow

(22mm)

Pressure Relief

Valve

(15mm)

Gas Inlet

(22mm)

95 mm

65 mm

Boiler Mounting Bracket Fixing Slots

Drill 8 mm diameter x 50 mm deep

65 mm 65 mm

65 mm

Boiler Lower Fixing Holes

Drill 8 mm diameter x 50 mm deep

921.936.1

Comp No 248740 - Iss 1 - 1/01

IMPORTANT

Pipework cannot be

rear routed upwards behind the boiler.

Keep pipework, electrical cables and clips clear of

all shaded areas to allow the correct fitting of the boiler

Fixing Template

Appliance Wall Plate

190mm

For Side Flue Exit

Central Heating Return

Flushing Tube

Wall Plate

Filling Loop

8.0 Installation

8.4 Fitting The Boiler

1. Remove the sealing caps from the boiler connections.

2. Lift the boiler using the lower edges. Engage the slots at the top rear of the boiler on the wall plate (Fig. 18).

3. Insert the sealing washers between the valves and pipes on the wall plate and the boiler connections. The rubber washers must be

used on the gas connection.

4. Tighten all the connections.

8.5 Fitting the Pressure Relief

Discharge Pipe (Fig. 19)

1. Remove the discharge pipe from the kit.

2. Determine the routing of the discharge pipe in the vicinity of the boiler. Make up as much of the pipework as is practical, including the discharge pipe supplied.

3. The pipework must be at least 15mm diameter and run continuously downwards to a discharge point outside the building. See section 6.7 for further details.

4. Utilising one of the sealing washers, connect the discharge pipe to the adaptor and tighten the nut.

5. Complete the discharge pipework and route it to the outside discharge point.

IMPORTANT: Make all soldered joints before connecting to the pressure relief valve.

Fig. 19

Fig. 18

Pressure Relief Valve

Wall Plate

Discharge Pipe

8.0 Installation

8.6 Fitting The Flue

HORIZONTAL FLUE

1. The standard flue is suitable for lengths 100mm minimum to 1m maximum (measured from the edge of the flue elbow outlet).

Rear Flue: maximum wall thickness - 900mm

Side Flue: maximum wall thickness - 870mm

2. Locate the flue elbow on the adaptor at the top of the boiler. Set the elbow to the required orientation (rear, right or left).

3. Measure the distance from the outside wall face to the elbow (Fig. 20). This dimension will be known as ‘X’.

4. Taking the air duct, mark dimension ‘X’ as shown (Fig. 21). Measure the length of waste material, and transfer the dimension to the flue duct (Fig. 21).

IMPORTANT: Check all measurements before cutting.

5. Remove the waste from both ducts. Ensure that the cut ends are square and free from burrs.

6. Remove the flue elbow from the adaptor.

7. Insert the flue duct into the air duct and pass them through the hole in the wall.

Wall Thickness

(X)

Wall Thickness

(X)

Fig. 20

Waste

(X)

Waste

Fig. 21

Air Duct

Flue Duct

8.0 Installation

8.6 Fitting the Flue (Cont)

IMPORTANT: If the equivalent flue length is

greater than 1.5m the restrictor MUST be removed from the adaptor (Fig. 22).

8. Take one of the rubber seals and position it on the boiler flue adaptor. Engage the flue elbow on the adaptor and pull the sleeve up so that it equally covers the joint (Fig. 22).

9. Remove the screws from one of the clips provided. Prise the clip apart and fit it over the seal (Fig. 23). Set the elbow to the required angle.

10. Refit the screws to the clip and tighten them to secure the elbow. Take the second rubber seal and position it on the flue elbow.

11. Locate the flue duct clamp on the flue outlet elbow. Draw the flue duct out of the air duct, engage it in the clamp and tighten the screws (Fig. 24).

12. Draw the air duct out of the wall and align it with the elbow. Position the seal so that it equally covers the joint (Fig. 25).

13. Remove the screws from the second clip provided. Prise the clip apart and fit it over the seal. Refit the screws to the clip and tighten them (Fig. 25).

14. Where possible position the clips so that the screws are not visible.

15. Make good between the wall and air duct outside the building.

16. Fit the circular flue trim outside if required, and if necessary fit a terminal guard (see Section 7.10 & 7.11).

8.7 Extensions & Additional Elbows

1. The method of connecting any flue extensions or additional elbows is the same as that for connecting the standard flue and 90° elbow as described above.

2. If, for example, when a flue extension is connected to a 90° elbow the flue duct will project from the air duct at the unconnected end by the same ammount as the flue duct spigot does from the elbow . Further elbows or extensions can then be added to this.

3. Similarly, a concentric flue can be connected to the boiler adaptor in the same manner as it does to the elbow to provide a vertical flue.

4. The additional 90° elbow available is identical to the elbow supplied with the standard flue. 45° elbows are of the same principle.

5. Extensions can be cut according to the requirements of the installation.

Fig. 22

Fig. 23

Fig. 24

Seal

Adaptor

Seal

Clip

Screws

Flue Duct Clamp

Flue Duct

Air Duct

Seal

Clip

Screws

Fig. 25

Restrictor

Elbow

8.0 Installation

8.8 Making The Electrical Connections

To connect the mains input cable proceed as follows:-

1. Slacken the facia panel securing screws and lift the outercase panel so that its securing tabs are clear of the facia. Remove the panel.

2. Remove the screws securing the facia panel and hinge it down (Fig. 26).

3. Remove the control box cover securing screws. Disengage the barbs on the control box from the cover. Remove the cover (Fig. 27).

4. Slacken the cable clamp on the LH side of the boiler chassis (Fig. 28). Insert the cable through the clamp and route it to the terminal block.

5. Slacken the screws in the terminal block, connect the input cable, and tighten the screws.

6. If an external control is to be connected it can be done at this point. Run the input cable from the external control through the second cable clamp on the boiler chassis. Refer to the instructions supplied with the control.

7. To connect external control(s) remove the link between terminals 1 & 2. The 230V supply at terminal 1 must be connected to the external control. The switched output from the external control must be connected to terminal 2. (Fig.

29).

NOTE: If the room thermostat being used incorporates an anticipator it MUST be wired as shown in Fig. 29

IMPORTANT: The external control MUST be suitable for 230V switching.

8. Ensure that both mains input and, where fitted, external control input cables have sufficient slack to allow the control box to drop down. Tighten the cable clamp(s) on the boiler chassis.

9. If the optional integral timer is to be used it should be fitted at this point. Refer to the instructions supplied with the timer. NOTE: An external frost thermostat cannot be used with the integral timer.

8.9 Preliminary Electrical Checks

1. Prior to commissioning the boiler preliminary electrical system checks should be carried out.

2. These should be performed using a suitable meter, and include checks for Ground Continuity, Resistance to Ground, Short Circuit and Polarity.

Always fit fast

blow 2A fuse

Fused supply 3A 230V ~ 50Hz

Live (brown)

Neutral (blue)

Earth (green/yellow)

230V

g/y

Frost Thermostat

Room Thermostat

External Clock

230 V

Selector /

Reset Switch

External Controls

br b

Pump

Hydraulic Differential Pressure Switch

DHW Flow Priority Microswitch

Safety Overheat Thermostat

Central Heating

NTC Sensor

Gas Valve

Spark Electrode

Spark

Generator

Flame Sensing Electrode

br b

Fan

bk bk

Pressure Switch

PCB

DHW

NTC Sensor

Gas Valve Modulator

Fig. 28

Fig. 27

Fig. 29

Fig. 30

Fig. 26

Terminal Block

Fuse

Cable Clamp

Control Box Cover

Facia Panel

Functional Flow Diagram

Key to Wiring

b - blue br - brown bk - black r - red g - green

IMPORTANT: If an integral timer is fitted to the boiler an external frost thermostat wired as shown will not operate correctly. Only external timers may be used in such installations, as in the diagram.

9.0 Commissioning the Boiler

9.1 Commissioning the Boiler

1. Reference should be made to BS 5449 Section 5 when commissioning the boiler.

2. Open the mains water supply to the boiler.

3. Open all hot water taps to purge the DHW system.

4. Ensure that the filling loop is connected and open, then open the heating flow and return valves on the boiler.

5. Open the screw on the automatic air vent (Fig. 31).

6. The system must be flushed in accordance with BS 7593 (see Section 6.2) and the flushing agent manufacturers instructions.

7. Pressurise the system to 1.0 bar then close and disconnect the filling loop.

8. Turn the gas supply on and purge according to in GB BS 6891 and in IE I.S. 813 “Domestic Gas Installations”.

9. Test for gas soundness.

10. If at any time during commissioning it is required to terminate a particular cycle, e.g. the pump overrun period, turn the selector to the OFF position and then back to either ( ) or ( ) (Fig. 33).

Automatic

Air Vent

Pressure

Gauge

Screw

bar

Fig. 31

Selector Switch

Central Heating

Temperature Control

Hot Water

Temperature Control

Fig. 32

30° 40° 50° 60° 70° 80°

bar

OFF

PREHEAT

Pump

Fig. 33

Power On

Neon

9.0 Commissioning the Boiler

OUT

MIN

Burner Pressure Test Point Sealing Screw

Fig. 34

9.2 Checking the Burner Pressure

1. Turn on the gas and electrical supplies to the boiler and ensure that all external controls are calling for heat.

2. Set the hot water and central heating temperature controls to maximum and the selector switch to the OFF position (Fig. 37).

3. Slacken the pressure test point sealing screw (Fig. 34) on the gas valve and connect a pressure gauge.

4. Disconnect the sensing tube from the gas valve (Fig. 34).

5. Turn the selector switch fully anticlockwise against the spring pressure to position R and hold for 2 seconds to reset the boiler.

6. Turn the selector switch to the Central Heating and Domestic Hot Water position ( ). The power ON neon ( ) will illuminate (Fig. 37).

7. Turn on a hot water tap to give a flow rate of at least 10 l/min.

8. The pressure should be :-

Instant Instant 80e 105e

NG 12.2mbar 13.4mbar Butane 28.3mbar n/a Propane 36.2mbar 35.8mbar

If not, check that the gas supply pressure is correct (Natural Gas 20mbar, Butane 30mbar and Propane 37mbar). Also check that the

working pressure at the gas valve is not more than 1mb lower than that at the gas meter.

9. The pressure can be adjusted if required.

10. To check and set minimum pressure first remove one of the modulator wires.

Adjusting the Pressure (Fig 35)

11. Remove the plastic protection cap from the pressure adjustment nuts on the valve.

12. The smaller nut (5mm) adjusts minimum pressure and the larger nut (8mm) maximum pressure.

13. Using a suitable spanner adjust the relevant nut until the correct pressure is achieved.

14. Once the pressure has been set turn the boiler off and disconnect the pressure gauge.

15. Tighten the pressure test screw and refit the modulator to the valve. Reassemble in reverse order.

Selector Switch

Central Heating

Temperature Control

Hot Water

Temperature Control

30° 40° 50° 60° 70° 80°

bar

OFF

PREHEAT

Fig. 37

Power On

Neon

Pressure

Gauge

bar

Fig. 36

Gas Valve

Fig. 35

Plastic Protection Cap

Modulator Wire

Maximum Rate Adjustment Nut

Minimum Rate Adjustment Nut

Inlet Pressure Test Point Sealing Screw

10.0 Completion

10.1 Completion

1. Hinge the facia panel upwards and refit the case front panel. Secure them with the screws previously removed (Fig. 38).

2. Instruct the user in the operation of the boiler and system, explaining the operational sequence.

3. Carefully read and complete all sections of the “Benchmark” Installation, Commissioning and Service Record Log Book that are relevant to the appliance and installation. The details of the Log Book will be required in the event of any warranty work. The Log Book must be handed to the user for safe keeping and each subsequent regular service visit recorded.

4. For IE, it is necessary to complete a “Declaration of Conformity” to indicate compliance with I.S. 813. An example of this is given in I.S. 813 “Domestic Gas Installations”. In addition it is necessary to complete the “Benchmark” Log Book.

5. Hand over the Users Operating, Installation and Servicing Instructions and the Log Book, giving advice on the necessity of regular servicing.

Fig. 38

Facia Panel

Case Front Panel

11.0 Servicing the Boiler

11 .1 Annual Servicing

1. For reasons of safety and economy, it is recommended that the boiler is serviced annually. Servicing must be performed by a competent person.

2. After servicing, complete the relevant section of the “Benchmark” Installation, Commissioning and Service Record Log Book. This should be in the possession of the user.

3. Ensure that the boiler is cool.

4. Ensure that both the gas and electrical

supplies to the boiler are isolated.

5. Slacken the screws securing the facia panel. Lift the outercase panel so that its securing tabs are clear of the facia. Remove the panel (Fig. 39).

6. Remove the screws (2 on Instant 80e, 4 on Instant 105e) securing the inner door panel. Lift the panel slightly to disengage it from the studs on top of the case (Fig. 40).

7. Note the positions of the two sensing tubes on the outlet elbow and three wires on the fan motor and remove them (Fig. 41).

8. Slacken the screws on the outlet sealing collar. Ease the collar upwards as far as possible (Fig. 41).

9. Remove the four screws securing the combustion box door and remove the door (Fig. 40).

Fan Wires

Fan

+’ve

-’ve

g/y

Sensing

Tubes

Outlet Sealing

Collar

Combustion

Box Door

Inner Door

Panel

Case Front Panel

Ease Outlet Sealing

Collar Upwards

Fig. 39

Facia Panel

Securing Screws

Fig. 41

Combustion

Box Door

Inner Door

Panel

Fig. 40

Instant 80e

models

Instant 105e

models

11.0 Servicing the Boiler

11.1 Annual Servicing (Cont)

10. Remove the spring clips retaining the air box side baffle plates. Disengage the tabs on the baffles from the slots in the fan hood (Fig. 42).

11. Undo the screws securing the fan and hood to the appliance back panel. Draw the assembly forwards (Fig. 42a).

12. Undo the screws securing the burner to the injector manifold (Instant 105e model only). Draw the burner out of the combustion box, pulling the electrode grommets from the slots in the combustion box lower panel (Fig. 43).

13. Disconnect the electrode leads and grommets from the electrodes. Completely remove the burner (Fig. 43).

14. Brush any deposits from the injectors. Do not use a pin or wire to clean them.

15. Brush the burner blades and venturis and clean the combustion box.

16. Ensure that the heat exchanger fins are clear of any obstruction.

DHW Filters (Fig. 44)

17. If the flow of domestic hot water is diminished, it may be necessary to clean the filters.

18. Initially check the cold water inlet tap filter.

19. Turn the tap off. Undo the blanking cap and remove the threaded bush (Fig. 43a).

20. Extract the filter and rinse thoroughly in clean water. Reassemble and check the flow. If required clean the manifold filter as described below.

21. Undo the filter cartridge from the inlet/return manifold.

22. Dismantle the cartridge and carefully remove the flow regulator and filter gauze. Rinse them thoroughly in clean water and reassemble in reverse order.

23. Check that the pressure vessel charge is

0.5bar and reassemble in reverse order of dismantling.

24. Turn the selector switch fully anticlockwise against the spring pressure to position R and hold for 2 seconds to reset the boiler before recommissioning.

25. Complete the relevant section of the “Benchmark” Installation, Commissioning and Service Record Log Book and hand it back to the user.

Spring Clip

Fan and Hood

Assembly

Baffle

Tab

Burner

Electrode

Grommets

Fig. 42

Fig. 43

Fig. 44

Cartridge

Body

Filter Gauze

Flow

Regulator

Venturi

Inlet/Return Manifold

Cold Water

Inlet Tap

Blanking

Cap

Threaded

Bush

Fig. 43a

Fig. 42a

12.0 Changing Components

IMPORTANT: When changing components ensure that both the gas and electrical supplies to the boiler are isolated before any work is started. When the new component has been fitted turn the selector switch fully anticlockwise against the spring pressure to position R and hold for 2 seconds to reset the boiler before recommissioning.

See Section 11.1 “Annual Servicing” for removal of case panel, door etc.

12.1 Pressure Switch (Fig. 45)

1. Note the positions of the two sensing tubes and three wires and remove them.

2. Remove the two screws holding the pressure switch to the combustion box top panel.

3. Fit the new pressure switch and reassemble all components in reverse order of dismantling.

12.2 Fan (Figs. 46 & 47)

1. Note the positions of the two sensing tubes on the outlet elbow and three wires on the fan motor and remove them.

2. Slacken the screws on the outlet sealing collar. Ease the collar upwards as far as possible.

3. Remove the four screws securing the combustion box door and remove the door.

4. Remove the spring clips retaining the air box side baffle plates. Disengage the tabs on the baffles from the slots in the fan hood.

5. Undo the screws securing the fan hood to the appliance back panel, and draw the fan and hood assembly forwards.

6. Remove the screws and spring washers securing the fan to the hood.

7. Fit the new fan to the hood using the screws and spring washers previously removed.

8. Reassemble in reverse order of dismantling.

Spring Clip

Fan

Fan Hood

Spring Washer

Securing Screw

Baffle

Tab

Fan Wires

Fan and Hood Assembly

Sensing Tubes

Outlet Sealing

Collar

Pressure Switch

Sensing Tubes

Pressure

Switch Wires

Fig. 45

Fig. 46

Fig. 47

+’ve

-’ve

g/y

+’ve

-’ve

12.0 Changing Components

12.3 Heat Exchanger (Fig. 48)

1. Note the positions of the two sensing tubes on the outlet elbow and three wires on the fan motor and remove them.

2. Slacken the screws on the outlet sealing collar. Ease the collar upwards as far as possible.

3. Remove the four screws securing the combustion box door and remove the door.

4. Remove the spring clips retaining the air box side baffle plates. Disengage the tabs on the baffles from the slots in the fan hood.

5. Undo the screws securing the fan hood to the appliance back panel, and draw the fan and hood assembly forwards.

6. Drain the primary circuit. Prise the two pipe connecting clips off the joints in the flow and return pipes.

7. Lift the heat exchanger to disconnect the flow and return pipe joints. Withdraw it from the appliance, taking care not to damage the rear insulation piece.

8. Fit the new heat exchanger.

9. Reassemble in reverse order of dismantling, and repressurise the system.

12.4 Burner (Fig. 49)

1. Remove the four screws securing the combustion box door and remove the door.

2. Undo the screws securing the burner to the injector manifold (Instant 105e model only). Draw the burner out of the combustion box, pulling the electrode grommets from the slots in the combustion box lower panel.

3. Disconnect the electrode leads and grommets from the electrodes. Completely remove the burner.

4. Undo the screws securing the electrodes to the burner. Examine the condition of the electrodes, replacing if necessary. Fit the electrodes to the new burner.

5. Engage the burner location brackets over the studs on the injector manifold and reassemble in reverse order.

Burner

Electrode

Grommets

Electrode

Leads

Electrodes

Fig. 48

Heat Exchanger

(Instant 105e model)

Pipe Connecting Clips

Fig. 49

Heat Exchanger

(Instant 80e model)

Pipe Connecting Clips

12.0 Changing Components

12.5 Injectors (Fig. 50)

1. Remove the burner as described in Section

12.4.

2. Undo the screws securing the injector manifold to the inlet elbow and remove the manifold.

3. Unscrew and replace injectors as required and examine the sealing gasket, replacing as necessary. Reassemble in reverse order.

12.6 Electrodes (Fig. 50)

1. Remove the four screws securing the combustion box door and remove the door.

2. Undo the screws securing the burner to the injector manifold (105e model only). Draw the burner out of the combustion box, pulling the electrode grommets from the slots in the combustion box lower panel.

3. Disconnect the lead and grommet from the electrode being replaced. Undo the securing screw and withdraw the electrode to the burner.

4. Reassemble in reverse order.

12.7 Insulation (Fig. 51)

1. Remove the four screws securing the combustion box door and remove the door.

2. Slide the side insulation pieces carefully out of their carriers.

3. To replace the rear insulation piece it is necessary to remove the heat exchanger as described in Section 12.3 and slide out the side pieces.

4. The combustion box door insulation piece can be replaced by carefully bending up the two retaining tabs.

5. Replace all insulation pieces and reassemble in reverse order.

13.8

Injector

Manifold

Inlet Elbow

Gasket

Injector

Burner

Electrode Grommets

Electrode

Leads

Side Insulation

Rear Insulation

Front Insulation

Combustion

Box Door

Side Insulation

Electrodes

Fig. 50

Fig. 51

12.0 Changing Components

12.8 Gas Valve (Fig. 52)

1. Undo the nut on the gas feed pipe under the boiler.

2. Remove the securing screws and hinge the facia panel down.

3. Disconnect the earth wire and pressure sensing pipe from the valve. Undo the screw securing the electrical plug to the valve and disconnect the plug. Disconnect the wires from the valve modulator.

4. Remove the screws securing the inlet pipe flange to the boiler bottom panel and those securing the outlet manifold to the burner manifold.

5. Remove the valve from the boiler.

6. Note the orientation of the inlet pipe and outlet manifold. Undo the securing screws and remove the pipe and manifold.

7. Examine the ‘O’ ring seals for damage, replacing as necessary.

8. Fit the inlet pipe and outlet manifold to the new valve, ensuring that the ‘O’ ring seals are in place.

9. Reassemble in reverse order and check the burner pressure (Section 9.2).

12.9 Central Heating Temperature Sensor

(Fig. 53)

1. Ease the retaining tab on the sensor away and disconnect the electrical plug.

2. Unscrew the sensor from it’s pocket and reassemble in reverse order. The electrical plug will only fit one way.

12.10 Safety Thermostat (Fig. 53)

1. Pull the electrical connections off the thermostat.

2. Remove the screws securing the thermostat to the mounting plate on the flow pipe.

3. Reassemble in reverse order. The thermostat is not polarised - either wire can fit either terminal on the thermostat.

12.11 DHW Temperature Sensor (Fig. 53a)

1. Turn off the mains water supply and draw off the residual domestic hot water.

2. Ease the retaining tab on the sensor away and disconnect the electrical plug.

3. Unscrew the sensor from the plate heat exchanger manifold. Examine the sealing washer,replacing if necessary.

4. Reassemble in reverse order. The electrical plug will only fit one way.

Gas Valve

Inlet Pipe

Gas Feed

Pipe

Earth Wire

Electrical

Plug

Central Heating

Temperature Sensor

Safety

Thermostat

Flow Pipe

Fig. 52

Fig. 53

DHW Temperature

Sensor

Fig. 53a

Plate Heat

Exchanger

Modulator

Wires

12.0 Changing Components

12.12 Pump - Head Only (Fig. 54)

1. Drain the primary circuit and remove the socket head screws securing the pump head to the body and draw the head away.

2. Undo the screw on the pump wiring cover and remove the cover. Using a suitable flat bladed screw driver press the cable securing levers downwards to release each wire after noting their position.

3. A standard Grundfos replacement head can now be fitted. A Grundfos 15-50 head is suitable for the Instant 80e. The Instant 105e requires a 15-60 head. Connect the wiring to the new head. The pump speed must be set to 3 (Fig. 55).

4. Reassemble in reverse order.

12.13 Pump - Complete (Fig. 56)

1. Drain the primary circuit and unscrew the automatic air vent from the pump body. Undo the two screws securing the body to the pipe and manifold and draw the pump forwards.

2. Undo the screw on the pump wiring cover and remove the cover. Using a suitable flat bladed screw driver press the cable securing levers downwards to release each wire after noting their position.

3. Connect the wiring to the new pump. Examine the ‘O’ ring seals on the return pipe and manifold, replacing if necessary.

4. Fit the air vent to the pump body and reassemble in reverse order.

12.14 Automatic Air Vent (Fig. 56)

1. Drain the primary circuit and unscrew the automatic air vent from the pump body.

2. Examine the ‘O’ ring seal, replacing if necessary, and fit it to the new automatic air vent.

3. Reassemble in reverse order.

Pump Setting

Pump Wiring

Cover

Socket Headed

Screw

Pump Head

Pump Body

Pump Wiring

Cover

Automatic

Air Vent

Fig. 54

Fig. 56

Fig. 55

12.0 Changing Components

12.15 Pressure Gauge (Figs. 57 & 58)

1. Drain the primary circuit and undo the nut on the pressure gauge capillary.

2. Remove the timer cover and ease the timer wiring aside. Undo the screws securing the gauge retaining bracket.

3. Remove the bracket and gauge assembly. Depress the barbs on the side of the gauge and remove the retaining bracket.

4. Reassemble in reverse order.

12.16 Expansion Vessel &

Pre-Heat Store(Fig. 59)

1. To replace the expansion vessel and pre-heat store it is necessary to remove the boiler from the wall.

2. Drain the system and undo all gas and water connections. Remove the flue elbow.

3. Lift the boiler off the wall plate and lay it on either side on a clean flat surface.

4. Undo the unions on pipe ‘A’ and remove the pipe (Fig. 59).

5. Undo the union on pipe ‘B’ connected to the vessel (Fig. 59) and remove the locknut securing the vessel spigot to the boiler chassis.

6. Undo the screws and remove the appliance upper cross member. Slide the expansion vessel and insulation out of the retaining clips.

7. Reassemble in reverse order using new sealing washers. Fully recommission the appliance and system.

12.17 Spark Generator (Fig. 60)

1. Pull the electrode lead off the spark generator. Remove the screws and spring washers securing the generator to it’s mounting bracket.

2. Pull the rubber shroud off the generator input plug and disconnect the plug.

3. Reassemble in reverse order.

Pressure Gauge

Timer Cover

Pressure Gauge

Capillary

Gauge Retaining

Bracket

Expansion Vessel

Retaining Clip

Appliance Upper

Cross Member

Vessel Spigots

Boiler

Chassis

Lock Nut

Electrode Lead

Spark Generator

Mounting Bracket

Fig. 57

Fig. 58

Fig. 59

Fig. 60

Pipe ‘B’

Pipe ‘A’

12.0 Changing Components

12.18 Pressure Relief Valve (Fig. 61)

1. Drain the primary circuit.

2. Disconnect the discharge pipe from the valve. Using a suitable hexagon key undo the grub screw sufficiently to release the valve.

3. Note the orientation of the valve, rotate it and withdraw it from the manifold.

4. Fit the new valve and ‘O’ ring seal and set to the previously noted orientation. Reassemble in reverse order.

12.19 P.C.B. (Fig. 63)

1. Note the settings of the temperature control knobs. Rotate the knobs fully anticlockwise and carefully pull them off the drive pins.

2. Remove the screws securing the control box cover and release the cover retaining barbs from their slots. Disengage the rear of the cover from the control box hinge pin (Fig. 62).

3. Note the position of all plugs and wires on the P.C.B. and disconnect them.

4. Undo the securing screws and remove the P.C.B. Transfer the control knob drive pins to the new P.C.B. and turn them fully anticlockwise.

5. Reassemble in reverse order, ensuring that the temperature controllers are reset to their previous positions.

12.20 Selector Switch

1. Turn the selector switch knob to the off position and carefully pull it off the facia.

2. Remove the screws securing the control box cover and release the cover retaining barbs from their slots. Disengage the rear of the cover from the control box hinge pin.

3. Note the position of the electrical connections and the orientation of the switch. Remove the electrical connections.

4. Remove the screws securing the switch to the facia panel.

5. Fit the new switch and reassemble in reverse order. Turn the knob to the required setting.

Pressure Relief Valve

Grub Screw

‘O’ ring seal

Discharge Pipe

Control Box Cover

P.C.B.

Selector

Switch

Facia

Selector Switch Knob

Temperature Control Knobs

Fig. 61

Fig. 62

Fig. 63

Drive Pins

12.0 Changing Components

12.21 Plate Heat Exchanger (Fig. 64)

1. Drain the primary circuit.

2. While supporting the heat exchanger undo the screws securing it to the brass manifolds.

3. Withdraw the heat exchanger upwards and to the left of the gas valve, taking care not to damage any wires or controls.

Seals

4. There are four rubber seals between the manifolds and heat exchanger which may require replacement.

5. Ease the seals out of the manifolds. Replace carefully, ensuring that the seal is inserted into the manifold parallel and pushed fully in.

6. When fitting the new heat exchanger note that the left hand location stud is offset towards the centre more than the right hand one.

7. Reassemble in reverse order.

12.22 Diverter Valve Assembly

(Figs. 65 & 66)

The diverter valve assembly comprises of a central heating pressure differential valve and a domestic hot water pressure differential valve. These are connected to a manifold which is joined to the plate heat exchanger.

DHW Pressure Differential Valve Diaphragm

(Figs. 65 & 66)

1. Turn off the mains water inlet tap and drain the domestic hot water by turning on a hot tap.

2. Prise off the spring clip retaining the microswitch. Pull the switch away.

3. Undo the sensing pipe nut from the valve and slacken the nut at the inlet manifold. Ease the pipe away from the valve.

4. Undo the screws securing the differential valve cover.

5. Carefully draw off the cover and remove the diaphragm, noting the orientation.

6. Fit the new diaphragm and reassemble in reverse order.

Plate Heat Exchanger

Rubber Seal

DHW Pressure

Differential Valve

Microswitch

Sensing Pipe

Thrust Plate

Pushrod

Diaphragm

Spring

Diaphragm

Fig. 64

Fig. 65

Fig. 66

Spring Clip

DHW Pressure

Differential Valve

Cover

Offset Stud

12.0 Changing Components

12.22 Diverter Valve Assembly (Cont)

CH Pressure Differential Valve Diaphragm

(Fig. 67)

1. Isolate the boiler from the central heating flow and return pipes and drain the boiler primary circuit.

2. Prise off the spring clip retaining the microswitch. Pull the switch away.

3. Undo the screws securing the differential valve cover.

4. Carefully draw off the cover and remove the diaphragm.

5. Fit the new diaphragm and reassemble in reverse order.

Diverter Valve Operating Head (Fig. 67)

1. Pull the 3-pin plug off the operating head and prise off the spring clip retaining the head to the valve body.

2. Lift the operating head away from the valve body.

3. Fit the new head and reassemble in reverse order.

12.23 Flow Regulator (Figs. 68 & 69)

1. Undo the filter cartridge from the inlet/return manifold.

2. Unscrew the venturi and remove the flow regulator.

3. Check the cleanliness of the filter gauze, rinsing thoroughly in clean water as necessary. Fit the new flow regulator and reassemble in reverse order.

Fig. 67

Cartridge

Body

Filter Gauze

Flow

Regulator

Venturi

Inlet/Return Manifold

Fig. 68

Fig. 69

Diverter Valve

Microswitch

Diverter Valve

Operating Head

3-pin Plug

Pushrod

Diaphragm

Spring

Diaphragm

Spring Clip

CH Pressure

Differential Valve

Cover

Spring Clip

13.0 Illustrated Wiring Diagram

- brown

- black

- blue

- red

br bk b r

- green

- green / yellow

- white

g g/y w

Optional Timers

Domestic Hot Water Temperature Sensor

Reset Selector Switch

Control PCB

334

23456

556789

Central Heating Temperature Sensor

Fan

Gas Valve

Overheat Stat

Microswitch

Air Pressure

Switch

Flame

Spark Generator

Mains Input

Fuse

Link

g/y

Sensing Electrode

bbbr b

bkbrbr

Microswitch

Pump

Diverter Valve

Operating Head

14.0 Fault Finding

Carry out initial fault finding checks

1. Check that gas, water and electrical supplies are available at the boiler. Electrical supply = 230V ~ 50 Hz. CH water system pressurised to 0.5 bar when the boiler is cold. The preferred minimum gas pressure is 19.5mbar (natural gas), 27mbar (butane) or 36mbar (propane).

2. Carry out electrical system checks, i.e. Ground Continuity, Resistance to Ground, Short Circuit and Polarity with a suitable meter. NOTE: These checks must be repeated after any servicing or fault finding.

3. Ensure all external controls are calling for heat and check all external and internal fuses. Before any servicing or replacement of parts ensure the gas and electrical supplies are isolated.

Refer to Section 13.0 “Illustrated Wiring Diagram” for position of numbered terminals Domestic Hot Water - Preheating Function - Follow operational sequence

Turn On/Off/Reset selector to position.

neon illuminated.

Turn preheat control to on. Preheating function starts after 25 seconds.

neon flashing.

Primary water diverted to

DHW preheating circuit.

Pump runs.

Primary flow switch

operated.

Fan runs at maximum

speed.

Air pressure switch proved.

Spark at ignition electrode

for up to 10 seconds.

Burner lights.

Burner output modulates to minimum heat input until a temperature of 75°C is detected by central heating NTC sensor.

Burner extinguishes.

Go to section ‘A’.

External controls and

where fitted, integral timer

calling for heat.

Go to section ‘L’.

Ensure controls are set to

demand and verify the

contacts are closed.

Go to section ‘M’.

neon flashing.

Go to section ‘B’.

neon flashing.

Go to section ‘C’.

neon flashing.

Turn the selector to reset.

neon flashing.

Go to section ‘D’.

Go to section ‘J’.

neon flashing.

Go to section ‘E’.

neon flashing.

Turn selector to the reset position. If the neon does

not extinguish go to

sections H and K.

Change main PCB.

Burner extinguishes after

10 seconds.

Go to section ‘F’.

neon flashing.

Go to section ‘I’.

Go to section ‘G’.

Fan stops.

Pump continues to

run for 30 seconds.

Operation

sequence correct

YES

NOTE: When instructed to turn the Selector to the reset position turn the Selector Switch fully anticlockwise against the spring pressure to position R and hold for 2 seconds to reset the boiler.

14.0 Fault Finding

Domestic Hot Water - Follow operational sequence

Primary flow switch

operated

Fan runs at max speed.

Pump runs

Turn preheat control to on.

Preheating function starts

after 25 seconds.

neon flashing.

Primary water is diverted from preheating circuit to

DHW heat exchanger.

neon illuminated

Air pressure switch proved.

neon flashing

Spark at ignition electrode

for up to 10 seconds.

neon flashing

Go to section ‘B’

neon flashing

Go to section ‘C’

neons flashing

Go to section ‘D’

neon flashing

Go to section ‘I’

Turn the selector to reset.

If regular resetting is

required or appliance still

does not operate

investigation is necessary.

neon flashing

Go to section ‘E’

YES

Turn On/Off/Reset selector to position.

neon illuminated.

Primary water diverted to

DHW preheating circuit.

Open DHW tap fully. DHW

flow switch operated.

Burner lights.

Burner output modulates to maintain temperature set at

preheat control.

Burner goes out.

Burner extinguishes after

10 seconds.

Close DHW tap.

DHW flow valve senses no

flow. DHW flow switch

released off.

Preheating function

restarts.

neon flashing

Go to section ‘A’.

Go to section ‘M’.

External controls and

where fitted, integral timer

calling for heat.

Go to section ‘L’.

Ensure controls are set to

demand and verify the

contacts are closed.

DHW flow rate more than

2.5 l/min.

Is mains water filter and

differential assembly

clean?

DHW flow valve diaphragm

damaged.

Replace diaphragm.

DHW flow valve rod

obstructed.

Continuity across DHW flow

microswitch terminals and

PCB - A5 connector

terminals 5 & 6

Replace DHW flow

microswitch.

Replace main PCB

Go to section ‘J’.

Turn selector to the reset position. If the neon does

not extinguish go to

sections H and K.

Change main PCB.

Go to section ‘F’.

Reduce the DHW flow rate.

If burner does not modulate

clean DHW temperature

sensor and DHW heat

exchanger. If modulation

does not occur go to

section ‘G’.

External controls and where

fitted, integral timer calling

for heat.

Fan stops.

Pump continues to

run for 30 seconds.

Operation

sequence correct

Ensure controls are set to

demand and verify the

controls are closed.

Go to section ‘L’.

YES

YES YES

YES

neon flashing

YES

14.0 Fault Finding

Turn selector to

neon illuminated.

Turn Central Heating

thermostat to maximum.

neon illuminated.

Go to section ‘A’.

neon flashing

Go to section ‘B’.

External controls calling for

heat and where fitted,

internal clock calling for

heat.

Ensure controls are set to

demand and verify the

contacts are closed.

Central Heating - Follow operational sequence

Primary water is diverted from preheating circuit to

CH system.

neon illuminated.

Primary flow switch

operated.

Pump runs.

Fan runs at max speed.

Air pressure switch proved.

Spark at ignition electrodes

for up to 10 seconds.

neon illuminated

Burner extinguishes after

10 seconds.

Preheating function starts

after 25 seconds.

neon flashing

(see DHW preheating

function).

Primary water is diverted from preheating circuit to

CH system.

neon illuminated

Go to section ‘M’.

neon flashing

Go to section ‘B’.

neon flashing

Go to section ‘C’.

neons flashing

Go to section ‘D’.

Turn the selector to reset.

If regular resetting is

required or appliance still

does not operate

investigation is necessary.

Go to section ‘J’.

YES

neon flashing

Go to section ‘E’.

neon flashing

Turn selector to the reset position. If the neon does

not extinguish go to

sections H and K.

Change main PCB.

Go to section ‘F’.

neon flashing

Go to section ‘I’

Preheat control is not at

minimum position. External

control calling for heat.

Go to section ‘L’.

Go to section ‘M’.

YES

NO YES

YES

neon flashing

Go to next page

14.0 Fault Finding

Burner output modulates

until set temperature is

reached.

Burner goes out.

Fan stops.

Pump continues to run

for 3 minutes.

(room thermostat open)

Operation

sequence correct

Go to section ‘G’.

YES

CH temperature higher

than set point of CH

thermostat control. When

CH temperature decreases

cycle continues.

Central Heating - Follow operational sequence (Continued)

Fan runs at max speed.

Air pressure switch proved.

Spark at ignition electrodes

for up to 10 seconds.

neon illuminated

Burner extinguishes after

10 seconds.

neons flashing

Go to section ‘D’.

Turn the selector to reset.

If regular resetting is

required or appliance still

does not operate

investigation is necessary.

Go to section ‘J’.

YES

neon flashing

Go to section ‘E’.

neon flashing

Turn selector to the reset

position. If the neon does

not extinguish go to

sections H and K.

Change main PCB.

Go to section ‘F’.

neon flashing

Go to section ‘I’

YES

neon flashing

Does the burner remain lit ?

Continued from

14.0 Fault Finding

Fault Finding Solutions

Is there 230V at:

Main terminals L and N Check electrical supply

Main terminal fuse

Replace fuse

Replace main PCB

neon

illuminated

YES

Selector terminals a & b and a & 3. PCB - A4 connector terminals 4 & 5

Check wiring Replace selector

Pump Replace pump

YES

PCB - A4 connector terminals

Replace main PCB

Change pump supply cable

YES

CH system pressure 0.5 to 1.5 bar Re-pressurise system

Primary flow valve diaphragm damaged

Replace diaphragm

Flow valve rod obstructed - clean, reset

YES

Check automatic air vent is open

Open the automatic air vent

YES

Continuity across flow microswitch and PCB - A5 connector terminals 7 & 8

Replace microswitch

1. NO

Temperature sensor faulty. Cold resistance approx. 11 kΩ (resistance reduces with increase in temp.)

Replace sensor

YES

Fan connections correct at fan. PCB - A2 connector 230V across terminals 5 & 7

Fan jammed or faulty winding

Replace main PCB

Replace fan

YES

If pump jammed, release

14.0 Fault Finding

Check and correct if necessary

1. Electrical and pressure tube connections

2. Blockage of pressure tubes

3. Restriction in flue

4. Venturi

Replace air pressure switch

Gas at burner

Ensure gas is on and purged

Replace main PCB

Replace gas valve

neon flashing

PCB - A1 connector has 230V

across terminals 2 & 4

YES

Turn selector switch

to reset position

YES

Replace main PCB

Check and correct if necessary

1. Ignition electrode and lead

2. Electrode connection

3. Spark gap and position

230V at Main PCB - A1 connector across terminals 3 & 5. Check wiring

YES

Replace igniter

YES

Check the burner setting pressure

(see Technical Data and Commissioning)

Voltage at modulating coil of gas valve is: Max. burner press.approx 9V DC (13V DC LPG) Min. burner press.approx 1V DC

Current at modulating coil of gas valve is: (Use an instrument with average function for this measure) 30 ÷ 230 mA DC (45 ÷ 310 mA DC - LPG gas)

Replace gas valve

Replace main PCB

Fault Finding Solutions

14.0 Fault Finding

Check and correct if necessary

1. Flame sensing electrode and lead connections

2. Flame sensing electrode position

Flame current should be 1 µA approx.

Replace main PCB

YES

Replace flame sensing electrode

YES

Ensure that mains input

terminal L is Live (230V) and

N is Neutral (0V)

Check terminal 1 of ON/OFF/RESET selector is in

connection with PCB - A4 connector terminal 2

Check electrical continuity across terminals 1 & a

on reset selector when turned to position

Replace ON/OFF/RESET selector

Replace main PCB

YES

Replace overheat

thermostat

YES

Overheat thermostat operated

or faulty, i.e. continuity across

thermostat terminals

Allow to cool. Continuity

across thermostat terminals

more than 1.5 ohm

Check continuity of loop on A10 connector

Replace main PCB

Is there 230V at:

Diverter valve operating head

Replace diverter valve operating head

2. PCB - A8 connector terminals

1 & 5 central heating function 1 & 3 DHW function

Replace main PCB

YES

Change motor supply cable

YES

Fault Finding Solutions

15.0 Short Parts List

Short Parts List

Key G.C. Description Manufacturers No. No. Part No.

22 E66 527 Fan 248002

23 393 974 Pressure Switch 247380

32 E66 393 Heat Exchanger (80e) 248016

E66 535 Heat Exchanger (105e) 248017

41 E66 398 Burner (80e) 248029

E66 399 Burner (105e) 248030

44 E66 402 Injector 248210

59 E66 408 Electrode Lead 248037

63 E66 411 Spark or Sensing

Electrode 247384

72 E66 431 Pump Complete (80e) 248041

E66 539 Pump Complete (105e) 248042

131 Temperature Sensor 5108265

135 E66 439 Safety Thermostat 248079

140 Gas Valve 5107339

141 Modulation Coil 5107340

154 E68 347 PCB 248731

169 E66 453 Pressure Gauge 248090

387 E68 349 Motor-3way Valve 248733

390 E68 350 Differential Valve-DHW 248734

140

154

135

169

131

390

387

Instant 80e models

Instant 105e models

Comp No248741 - Iss 6 - 4/03

922.555.2

BAXI POTTERTON

A Trading Division of Baxi Heating UK Ltd

Brownedge Road Bamber Bridge Preston Lancashire PR5 6SN After Sales Service 08706 096 096 Technical Enquiries 08706 049 049 Website www.baxi.co.uk

company

baxi Instant 105e User guide

Specifications and Main Features

Frequently Asked Questions

User Manual