9. ACCESS TO BOILER CONTROL COMPONENTS
▶ Remove 3 screws (A) and remove cover from control.
10. PCB FUSE
▶ Remove fuse (B) from the PCB and replace.
▶ There is a spare fuse clipped into the cover.
9.
10.
Fig. 62 Component and fuse access
11. PCB REMOVAL
To gain access to the PCB:
▶ Remove the five screws shown in the diagram below and remove the
PCB cover.
Fig. 63 PCB access
6 720 806 548 (2013/02)
A
B
12. FAN ASSEMBLY
NOTICE: Air/Gas ratio
▶ After re-assembly the combustion must be checked
using the procedure in the section "Setting the air/gas
ratio."
▶ The setting of the gas ratio must be carried out by a
competent person.
Setting the air/gas ratio must not be attempted unless
the person carrying out the operation is equipped
with a combustion analyser conforming to BS 7927
and is competent in its use.
▶ Remove electrical connector from fan.
▶ Remove condensate trap (see page 36).
1. Undo the union connection (A) from the top of the gas valve.
▶ Remove wire clip (B) from air/gas adjustment assembly (C) then pull
gas pipe down.
2. Unscrew two screws (D).
3. Remove fan from boiler.
4. Remove three screws retaining the air/gas adjustment assembly (E).
▶ Reassemble with new fan assuring that seals are correctly fitted.
C
1.
B
A
2.
D
Fig. 64 Fan assembly removal
13. ELECTRODE ASSEMBLY
WARNING: Electrode gasket
▶ Do not remove the electrode assembly unless a new
gasket is available for re-assembly.
▶ Disconnect spark electrodes and flame sensor connection.
▶ Remove two screws (F).
▶ Remove spark/flame electrode assembly (G) from heat exchanger.
▶ Inspect the spark/flame electrode assembly and ceramics for signs of
contamination or damage, replace as necessary.
▶ If necessary, clean the spark/flame electrode assembly with a plastic
scouring pad.
▶ Replace electrode gasket.
SERVICING AND SPARES
3.
8.
4.
E
37