Air/Gas Flap Valve Assembly; Ignition Transformer; Electrode Assembly; Burner Housing, Burner/ Gasket - Worcester Greenstar 25Si Compact Installation, Commissioning And Servicing Instructions

SERVICE AND SPARES
When refitting the rubber gas pipe, ensure that the pipe
is correctly oriented by aligning the notch in the pipe
with the lug on the fan connector. Do not kink the pipe.
There is a raised arrow on the pipe indicating the location
of the notch.
6.
Fig. 92 Fan removal 2

7.8.11 AIR/GAS FLAP VALVE ASSEMBLY

1. Remove the single screw securing the air/gas flap valve assembly.
2. Pull the flap assembly away from the housing.
2.
Fig. 93 Air/gas flap valve

7.8.12 IGNITION TRANSFORMER

To remove the ignition transformer
▶ Isolate the boiler electrically.
▶ Remove the combustion air inlet pipe.
▶ Ensure that the harness wires are disconnected from the transformer.
▶ Remove the electrode cables.
▶ Lift the transformer from the retaining clip.
50
5.
Fig. 94 Ignition transformer

7.8.13 ELECTRODE ASSEMBLY

7.
To remove the spark electrode assembly:
1. Undo and remove the two nuts securing the electrode assembly
2. Rotate the electrode assembly down and forward to remove from the
▶ Inspect the spark electrodes (2), ionisation probe (3) and ceramics
1.
▶ If necessary, clean the spark electrodes and ionisation probe with a
▶ Re-assemble with a new electrode gasket (1),
Fig. 95 Electrode assembly

7.8.14 BURNER HOUSING, BURNER/ GASKET

To remove the burner housing.
1. Release and remove the four spring pins from the castellated nuts.
CAUTION: Component replacement:
▶ After replacement of a gas related component, where
a gasket or seal has been disturbed or replaced, check
for gas tightness using a gas sniffer/analyser.
▶ Also after re-assembly, carry out the following
checks:
Fan pressure in section 7.5,
Flue gas analysis in section 7.6.
Heat exchanger.
for signs of contamination or damage, replace as necessary.
plastic scouring pad.
1
2.
2
1.
The front two bolts retaining the burner housing are NOT
captive and will drop out when the nuts are removed.
Greenstar Si Compact
3
ErP - 6 720 813 278 (2015/07)