PCB Control Box
Securing Screw
PCB Control 
Box
Boiler Front
Panel
Spark
Generator
Electrode
Assembly
Injector
Gas Feed
Pipe
Fan 
Fig. 44
Reset Switch
Off Position
Fig. 43
Sensing Pipe
Gas Valve
Discharge Pipe
Locking Clip
Condensate Pump
9.0 Annual Servicing
9.2Annual Servicing - Inspection
1.Ensure that the boiler is cool.
2.Ensure that the gas supply to the boiler is isolated.
3.Operate the Reset switch (Fig. 41) to activate the condensate pump and then repeat. This will empty most of the condensate from the sump.9. Isolate the boiler from the electrical supply.
4.Undo &remove the flue sampling plug and washer. Remove the screws retaining the boiler front panel, and lift the panel away (Fig. 43).
5.Remove the screw securing the PCB control box and swing the box to the right (Fig. 43).
6.Disconnect the two plugs from the fan motor and remove the sensing pipe from between the gas valve and fan outlet.
7.Remove the gas feed pipe and washers, and extract the injector from the gas/air inlet manifold.
8.For ease of access disconnect the following:-
a)2 pin plug on NTClead
b)all wires from electrode assembly
c)all wires from spark generator
d)both wires from the overheat thermostat
e)the red and black wires connected together
9.Undo the two securing nuts and remove the spark generator and bracket.
10.Undo the combustion panel securing nuts and remove the special spring washers. Remove the complete fan & panel assembly from the boiler.
11.Lay the assembly to one side. The outer insulation panel is fitted to the rear of the combustion box panel.
12.Clean inside the heat exchanger and examine the condition of the fins.
13.Examine the burner, electrodes, insulation and seal, replacing if necessary. Also check the condition of the three insulation pieces in the rear of the heat exchanger.
14.Disconnect the wires on the condensate pump motor and pull off the plastic discharge pipe. Cut and remove the transit cable tie. It is not necessary to replace this item.
15.Squeeze the two retaining clips and turn the pump anticlockwise to remove it. Draw it upwards from the sump.
16.Clean any debris from the sump and examine the condition of the pump seal, replacing if necessary.
17.Reassemble in reverse order of dismantling, checking and replacing any components as necessary. Recommission the boiler and complete the relevant Service Interval Record section of the Benchmark Commissioning Checklist at the rear of this publication.
28© Baxi Heating UK Ltd 2009
