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3

Legislation

4

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

21

9.0

Commissioning the Boiler

26

10.0

Completion

28

11.0

Servicing the Boiler

29

12.0

Changing Components

31

13.0

Illustrated Wiring Diagram

41

14.0

Fault Finding

42

15.0

Short Parts List

49

Section

Page

Contents

Summary of Contents for BAXI COMBI INSTANT 105 HE

Page 1: ...Baxi Combi Instant 80 HE Baxi Combi Instant 105 HE Gas Fired Wall Mounted Condensing Combination Boiler Installation Servicing Instructions Please leave these instructions with the user S t h e ...

Page 2: ...n 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 t...

Page 3: ...0 Dimensions and Fixings 11 6 0 System Details 12 7 0 Site Requirements 15 8 0 Installation 21 9 0 Commissioning the Boiler 26 10 0 Completion 28 11 0 Servicing the Boiler 29 12 0 Changing Components 31 13 0 Illustrated Wiring Diagram 41 14 0 Fault Finding 42 15 0 Short Parts List 49 Section Page Contents ...

Page 4: ... 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 ...

Page 5: ...purpose designed flues such as the standard horizontal flue kit part no 5111073 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 st...

Page 6: ...On Off Reset Selector Switch 22 Central Heating Temperature Control 23 Domestic Hot Water Pre Heat Control 24 Flame Failure or Blocked Condensate Drain 25 Safety Thermostat Activated Boiler or Flue 26 Fault on Fan or Flue 27 Fault on Pump or Low System Pressure 28 Fault on Hot Water Sensor 29 Fault on Central Heating Sensor 30 Power On 31 Domestic Hot Water Mode 32 Central Heating Mode 33 Burner O...

Page 7: ...p 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 heati...

Page 8: ...d 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 c...

Page 9: ...earances Above Casing 200 mm Min Below Casing 200 mm Min Front 450 mm Min For Servicing Front 5 mm Min In Operation L H Side 5 mm Min R H Side 5 mm Min In Operation 20 mm Min See Note NOTE The boiler can be operated with a clearance of 5mm at the right This is also sufficient for routine maintenance However a clearance of 20mm is required if it is necessary to remove the secondary heat exchanger T...

Page 10: ...Clearances Above Casing 200 mm Min Below Casing 200 mm Min Front 450 mm Min For Servicing Front 5 mm Min In Operation L H Side 5 mm Min R H Side 5 mm Min In Operation 20 mm Min See Note NOTE The boiler can be operated with a clearance of 5mm at the right This is also sufficient for routine maintenance However a clearance of 20mm is required if it is necessary to remove the secondary heat exchanger...

Page 11: ...mm Ø Min E 185mm F 190mm G 131mm 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 65 mm Tap Rail 360 Orientation Tube Ø 100mm D C B A E G F 3o 28mm Condensate Drain ...

Page 12: ...ms flux will be evident within the system which can lead to damage of system components All systems must be thoroughly drained and flushed out The recommended flushing and cleansing agents are Betz Dearborn Sentinel X300 or X400 and Fernox Superfloc Universal Cleanser which should be used following the flushing agent manufacturer s instructions System additives corrosion inhibitors and flushing ag...

Page 13: ... 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 For GB refer to BS 7074 Pt 1 For IE the current edition of I S 813 Domestic Gas Install...

Page 14: ...y 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 r...

Page 15: ...stic 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 9 10 1 A flat vertical area is required for the installation of the boiler 2 These dimensions include the ne...

Page 16: ...ork 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 supp...

Page 17: ...is increased to 32mm 8 If the boiler is fitted in an unheated location the entire condensate discharge pipe should be treated as an external run 9 In all cases discharge pipe must be installed to aid disposal of the condensate To reduce the risk of condensate being trapped as few bends and fittings as possible should be used 10 When discharging condensate into a soil stack or waste pipe the effect...

Page 18: ...mm A Directly 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 carp...

Page 19: ...c 7 9 Flue Trim 1 The rubber flue trim supplied may be fitted to either the outside wall or on the inner wall of installation 7 10 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...

Page 20: ...to consideration Their equivalent lengths are Concentric Pipes 45 bend 0 5 metres 93 bend 1 0 metres Twin Flue Pipe 45 bend 0 25 metres 91 5 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 optiona...

Page 21: ...diameter 116mm 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 Flushin...

Page 22: ...harge 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 8 6 Condensate Drain see section 7 6 1 Connect the condensate drain us...

Page 23: ...lbow on the adaptor at the top of the boiler Set the elbow to the required orientation Fig 21 NOTE The flue elbow is angled at 93 degrees to ensure a fall back to the boiler 3 Measure the distance from the outside wall face to the elbow This dimension will be known as X Fig 22 4 To dimension X add 50mm This dimension to be known as Y IMPORTANT Check all dimensions before cutting Wall Thickness X W...

Page 24: ...bly Fig 24 8 Insert the flue through the hole in the wall Fit the elbow to the boiler adaptor ensuring that it is pushed fully in 9 Draw the flue back through the wall and engage it in the elbow It may be necessary to use soap solution or similar to ease assembly of the elbow adaptor and flue Fig 25 10 Make good between the wall and air duct outside the building 11 Fit the flue trim if required an...

Page 25: ...l 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 pre...

Page 26: ...lushing 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 positi...

Page 27: ...1 8mbar 32 3mbar If not check that the gas supply pressure is correct Natural Gas 20mbar and Propane 37mbar 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 la...

Page 28: ...on 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...

Page 29: ...ve the screws 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 fan spigot 105 model Only one tube on 80 model and three wires on the fan motor and remove them Fig 41 8 Slacken the screws on the fan spigot outlet pipe clamps Ease the clamps inwards over the pipe 105 9 On 80 models undo...

Page 30: ...water is diminished it may be necessary to clean the filters 19 Initially check the cold water inlet tap filter 20 Turn the tap off Undo the blanking cap and remove the threaded bush Fig 45 21 Extract the filter and rinse thoroughly in clean water Reassemble and check the flow If required clean the manifold filter as described below 22 Undo the filter cartridge from the inlet return manifold 23 Di...

Page 31: ...r 6 Ease the front edge of the left hand baffle upwards disengaging the spring clip Disengage the tab on the baffle from the slot in the fan hood 7 Undo the screws securing the fan hood to the appliance back panel and draw the fan and hood assembly forwards 8 Remove the screws and spring washers securing the fan to the hood 9 Fit the new fan to the hood using the screws and spring washers previous...

Page 32: ...securing the combustion box door and remove the door 2 Undo the screws securing the burner to the injector manifold 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...

Page 33: ...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 53 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 Sec...

Page 34: ...er and check the burner pressure Section 9 2 12 9 Central Heating Temperature Sensor Fig 55 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 55 1 Pull the electrical connections off the thermostat 2 Remove the screws securing the ...

Page 35: ...mp 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...

Page 36: ...e 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 Condensate Trap Fig 63 1 Disconnect the two sensing wires from the trap connections 2 Squeeze together the wire spring clip t...

Page 37: ...onnect 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 Fig 66 1 Turn the selector switch knob to the off position and carefully pull it off the facia 2 Completely undo the scr...

Page 38: ...ve 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 68 69 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 microswit...

Page 39: ...rating 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 71 72 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 wate...

Page 40: ...e outer drum by easing it forward 7 Reassemble in reverse order of dismantling 12 25 Flue Overheat Thermostat Fig 74 NOTE The flue overheat thermostat includes a reset button Check that the thermostat will not reset before replacing 1 Remove the fan spigot outlet pipe from the fan and elbow 2 Pull the two wires off the terminals on the flue overheat thermostat Unscrew the thermostat from the adapt...

Page 41: ... 6 10 9 8 7 6 5 4 3 2 1 4 5 5 6 7 8 9 Central Heating Temperature Sensor Fan Gas Valve Overheat Stat Flue Stat Microswitch Air Pressure Switch Flame Mains Input Fuse Link g y b br br b g y Sensing Electrode b b b bk b b bk br br br Microswitch Pump Diverter Valve Operating Head bk bk w bk r b br br bk br b br b bk b bk br bk b br bk w r br b bk b r b bk br r bk bk w A5 A4 A8 A3 A2 A1 1 2 3 4 r r g...

Page 42: ...peed 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 G...

Page 43: ...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...

Page 44: ...ing 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 secti...

Page 45: ...ressure 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 O NO YES neon flashing Go to section E neon flashing Turn selector to the reset position If the neon doe...

Page 46: ...H system pressure 0 5 to 1 5 bar Re pressurise system 1 NO Primary flow valve diaphragm damaged Replace diaphragm Flow valve rod obstructed clean reset 3 YES Check automatic air vent is open Open the automatic air vent 2 NO NO C YES Continuity across flow microswitch and PCB A5 connector terminals 7 8 Replace microswitch 1 NO NO Temperature sensor faulty Cold resistance approx 11 kΩ resistance red...

Page 47: ...d 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 NO YES H YES Check the burner setting pressure see Technical Data and Commissioning 1 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 g...

Page 48: ...ed or faulty i e continuity across thermostat terminals Allow to cool Continuity across thermostat terminals more than 1 5 ohm J Check continuity of loop on A10 connector L Replace main PCB Is there 230V at Diverter valve operating head Replace diverter valve operating head 1 2 PCB A8 connector terminals 1 5 central heating function 1 3 DHW function NO M Replace main PCB YES Change motor supply ca...

Page 49: ...10 59 E66 408 Electrode Lead 248037 63 E66 411 Spark or Sensing Electrode 247384 72 E66 539 Pump Complete 248042 131 Temperature Sensor 5108265 135 E66 439 Safety Thermostat 248079 140 Gas Valve 5107339 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 371 Igniter Gas Valve Cable 5112385 A Flue Overheat Thermostat...

Page 50: ...16 0 Notes 50 ...

Page 51: ...16 0 Notes 51 ...

Page 52: ... 04 BAXI POTTERTON A Trading Division of Baxi Heating UK Ltd Brownedge Road Bamber Bridge Preston Lancashire PR5 6UP After Sales Service 08706 096 096 Technical Enquiries 08706 049 049 Website www baxi co uk company 923 612 1 ...

Page 53: ...nt 80 HE Baxi Combi Instant 105 HE Gas Fired Wall Mounted Condensing Combination Boiler User s Operating Instructions Please keep these instructions safe Should you move house please hand them over to the next occupier ...

Page 54: ...pe you get a satisfactory service from Baxi If not please let us know Natural Gas Baxi Combi Instant 80 HE G C No 47 075 17 Baxi Combi Instant 105 HE G C No 47 075 19 The boiler meets the requirements of Statutory Instrument The Boiler Efficiency Regulations 1993 No 3083 and is deemed to meet the requirements of Directive 92 42 EEC on the energy efficiency requirements for new hot water boilers fi...

Page 55: ...00 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 mu...

Page 56: ... leaks 1 If a gas leak is found or suspected turn off the gas supply at the meter immediately and at the isolating valve on the boiler if possible Contact your Gas Supplier immediately 1 3 Servicing your Appliance 1 For reasons of safety and economy your appliance should be serviced annually Servicing must be performed by a competent person Your Installer or Service Engineer will be able to advise...

Page 57: ...ture 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 item 13 of Fig 3 2 3 Facia Panel 1 The facia panel is behind the hinged lower door panel As well as the on off reset selector switch central heating temperature control knob pre heat control and pressure g...

Page 58: ...s 5 Position ii In this position hot water will be provided when a tap or shower is turned on Fig 8 The hot water neon will illuminate Fig 5 6 The boiler will light automatically on demand 7 The orange burner on neon will illuminate when the boiler is operating and the main burner is on Fig 5 IMPORTANT When the selector switch is in the 0 Off position the electrical supply to the boiler is isolate...

Page 59: ...e will operate 8 With the control in the OFF position Fig 11 the pre heat feature will not operate Hot water will be supplied at approximately 50 C 9 The pre heat feature will function with the selector switch in either operating position This is indicated by the domestic hot water mode neon flashing Fig 12 10 The flow rate can be reduced down to as low as 2 5 litre min The boiler will still recog...

Page 60: ...e terminal is blocked or obstructed in some way or that there is an internal fault If there is no external blockage of the flue terminal that can be easily removed contact your Installer or Service Engineer Fig 14 3 6 Pump Fault or Low Pressure 1 The neon will illuminate if the circulating pump is faulty or the system pressure drops below the minimum requirement Fig 14 2 Check the pressure gauge a...

Page 61: ...old weather the boiler and whole system should be drained unless there is additional frost protection 3 Your installer will advise you about frost protection and draining the system 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 i...

Page 62: ...ich must be kept free from obstruction as this would interfere with the correct operation of the boiler 4 The boiler may be installed in a cupboard if these minimum clearances are kept The compartment should be large enough to house the boiler and ancillary equipment only 5 IT SHOULD NOT BE USED AS A STORAGE CUPBOARD 4 2 Check List 1 If a fault develops or is suspected call your Installer or Servi...

Page 63: ...l number and serial number can be found on the information label on the back of the hinged lower door panel see back page 5 3 Guarantee 1 Your Baxi Combi Instant 80 HE or 105 HE is designed and produced to meet all the relevant Standards 2 Baxi provide a 12 month guarantee on the boiler The guarantee operates from the date installation is completed for the customer who is the original user 3 To ma...

Page 64: ...nical Enquiries 08706 049 049 Website www baxi co uk company When contacting Baxi Potterton please have the following information to hand Appliance Name Model Number Serial Number A label giving these details is situated on the rear of the hinged lower door panel attached to the users operating instruction label Label Lower Door Panel Users Operating Instruction Label 923 611 1 ...

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