COMBI A - Instruction Manual

SERVICING INSTRUCTIONS

SERVICING INSTRUCTIONS 18 REPLACEMENT OF PARTS ........................................................................................................................ 43 18.1 TO GAIN GENERAL ACCESS ................................................................................................................ 43 18.1.1 Removing the front panel...................................................................................................................... 43 18.1.2 Lowering the control panel.................................................................................................................... 43 18.2 ACCESS TO THE COMBUSTION CHAMBER........................................................................................ 44 18.2.1 Removing the combustion chamber front panel ................................................................................... 44 18.2.2 Removing the burner ............................................................................................................................ 45 18.2.3 Removing the detection electrode ........................................................................................................ 45 18.2.4 Removing the ignition electrode............................................................................................................ 45 18.2.5 Removing the fan.................................................................................................................................. 46 18.2.6 Removing the gas valve........................................................................................................................ 46 18.2.7 Removing the heat exchanger.............................................................................................................. 47 18.2.8 Removing the spark generator.............................................................................................................. 47 18.3 ACCESS TO THE WATER CIRCUIT ...................................................................................................... 48 18.3.1 Drain down............................................................................................................................................ 48 18.3.2 Removing the 3 way valve.................................................................................................................... 48 18.3.3 Removing the float of the flow switch ................................................................................................... 48 18.3.4 Removing the secondary heat exchanger ............................................................................................ 49 18.3.5 Removing the pump.............................................................................................................................. 49 18.3.6 Removing the pressure relief valve ..................................................................................................... 50 18.3.7 Removing the domestic expansion vessel............................................................................................ 50 18.3.8 Removing the overheat thermostat....................................................................................................... 50 18.3.9 Removing the temperature sensors (NTC’s) ........................................................................................ 50 18.3.10 Removing the pressure gauge.............................................................................................................. 50 18.3.11 Removing the DHW flow switch............................................................................................................ 51 18.4 ACCESS TO THE CONTROL SYSTEM.................................................................................................. 51 18.4.1 Removing the PCB’s............................................................................................................................. 51 18.4.2 Removing the fuses.............................................................................................................................. 52 18.5 CONNECTING THE EXTERNAL SENSOR ............................................................................................ 52 19 INCORRECT FUNCTION ............................................................................................................................. 53 20 MAINTENANCE INSTRUCTIONS ................................................................................................................ 54 20.1 GENERAL REMARKS ............................................................................................................................. 54 20.2 CLEANING THE PRIMARY EXCHANGER ............................................................................................. 54 20.3 OPERATIONAL TEST ............................................................................................................................. 55 21 SHORT SPARES LIST ................................................................................................................................. 56 22 NOTES.......................................................................................................................................................... 57 23 TECHNICAL DATA ....................................................................................................................................... 58 24 BENCHMARK COMMISSIONING CHECKLIST ........................................................................................... 60 25 SERVICE INTERVAL RECORD ................................................................................................................... 61 TERMS AND CONDITIONS OF GUARANTEE ............................................................................................ 64 INTRODUCTION The COMBI A is a fully automatic, wall mounted, low water content condensing combination boiler. It is a room sealed, fan assisted, appliance providing central heating and mains pressure domestic hot water on demand. It has electronic ignition and is suitable for all modern electrical control systems. The boiler is designed for sealed systems only and a circulating pump, expansion vessel together with a pressure gauge and safety valve are included within the boiler. The COMBI A range of boilers are domestic gas boilers and intended for domestic use only. 4

USER INSTRUCTIONS 1. Control Panel 16 29 26 25 27 28 30 Fig. 1 31 32 33 34 Control panel (Fig. 1) 16.- Pressure gauge 25.- Display 26.- On/off push button and power on indicator light 27.- Yellow indicator - Comfort button 28.- Reset push button and red indicator lock-out light 29.- DHW control knob and temperature setting 30.- Central Heating control knob and temperature setting 31.- Menu button 32.- Reducing button 33.- Increasing button 34.- Setting button Connecting bracket Taps shown in Open position (Fig. 2) 39.- Gas Service Tap 40.- Water Service Tap 41.- Central Heating Flow Isolating Valve 42.- Central Heating Return Isolating Valve 43 & 44.- Filling Taps 45.- Filling Loop 41 42 43 44 Fig. 2 45 39 40 5