andrews COMBIflo 100/300, Installation, Operation And Maintenance Manual

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ANDREWS COMBIfl o 54 GB
6.2 REMOVING AND CHANGING COMPONENTS
WARNING
None of the controls are repairable, if they are not functioning they MUST be replaced. In all cases,
before work commences turn off the mains electricity and gas supply.
The following items can be replaced:
1. Pressure and temperature relief valves
2. Flow, return and DHW Flow sensors
3. Low Loss Header and DHW tank sensors
4. Flue sensor
5. The appliance GUI display
6. Master and slave PCBs
7. Spark generator
8. Spark and sense electrodes
9. Plate heat exchanger
10. Gas valve
11. Air control tube and air control fl ap
12. Combustion fan
13. Venturi
14. Heat exchanger
15. Water pressure sensor
16. Heat engine circulation pump
17. Primary DHW pump
18. Secondary DHW pump
6.2.1 PRESSURE TEMPERATURE RELIEF VALVE
Th
e removal of this valve will require either the draining or the valving off of the system that is above tank level.
Once Isolated the connecting pipework can be removed and the valve unscrewed from the tank.
6.2.2 RETURN, FLOW AND DHW FLOW SENSORS
The Flow and return sensors are clipped on to the copper pipework beneath the heat exchangers. The DHW Flow
sensor is clipped to the DHW tank charging pipe on the left side of tank.
Flow & return sensors
• Unclip the sensor from the pipe and carefully pull off (do not pull on the wires) the connectors.
• Replacement is the reverse.
6.2.3 LOW LOSS HEADER AND DHW TANK SENSORS
Securing screw
The LLH sensor is fi tted into the top of the LLH in the rear top left hand side of the appliance.
• Undo the securing screw and withdraw sensor from pocket.
• Unplug connector from loom.
• Cut off securing tie and remove sensor.
• Replacement is the reverse