Bosch Worcester Greenstar CDi Classic System ErP Series - Fan, Air;Gas Manifold, Burner Procedures

SERVICING AND SPARES
6 720 815 724 (2015/11) 45
12. Fan assembly
▶ Remove electrical connector from fan.
▶ Remove the siphon/condensate trap.
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.
Fig. 79 Fan assembly removal
13. Electrode 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.
▶ Re-assemble with the new gasket and secure with the screws (F)
removed earlier.
Fig. 80 Electrode assembly
14. Air/gas manifold
1. Remove cover panel (A) by removing screws (B).
▶ Check that the boiler is completely isolated from the gas supply.
Fig. 81 Top panel
2. Remove clips (C) and unscrew the two bolts (D).
▶ Unscrew and remove the two hexagon screws (E) securing the fan.
▶ Slacken fully the rear securing bolt (F).
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 conversion is
equipped with a combustion analyser conforming to
BS 7927 and is competent in its use.
B
C
A
D
2.
1.
E
8.
3.
4.
6 720 812 176-25.1O
WARNING: Electrode gasket
▶ Do not remove the electrode assembly unless a new
gasket is available for re-assembly.
WARNING: Air/Gas manifold
▶ Do not remove the manifold unless a new gasket is
available for re-assembly.
13
G
F
6 720 812 175-20.1O
AB
6 720 812 175-15.1O
B
1.