Description Of Various Maintenance Operations; 10.1.1 Draining The Boiler; Checking Heat Exchanger, Burner And Electrodes - Worcester GREENSTAR 24 Installation, Commissioning And Servicing Instructions

– Electronic flue gas emission meter for CO
temperature
– Pressure gauge for 0 - 30 bar (resolution at least 0.1 bar)
• Special tools are not required
▶ Use 8 719 918 658 0 as heat conducting paste.
▶ Only use genuine spare parts!
▶ Refer to the spare parts catalogue when ordering spare parts.
▶ Always renew seals and O-rings removed during servicing or repair
work.
AFTER INSPECTION/MAINTENANCE
▶ Retouching all threaded fittings that have been undone.
▶ Readmission the appliance ( page 28).
▶ Check all connections for leaks.
▶ Check the gas-air ratio and adjust if necessary ( page 39).
10.1 DESCRIPTION OF VARIOUS MAINTENANCE
OPERATIONS
RETRIEVING LAST FAULT SAVED (SERVICE FUNCTION 6.A)
▶ Select service function 6.A ( page 36).
An overview of fault codes is given on page 48.

10.1.1 DRAINING THE BOILER

Many of the tasks in this section require that the appliance be isolated
from the gas and electrical mains and drained.
CENTRAL HEATING SYSTEM
To drain the boiler:
▶ Connect a suitable hose firmly to the drain point and run the hose
outside to a suitable point or container.
▶ Turn the drain valve a ¼ turn anticlockwise to open the drain valve
and drain. Turn the valve firmly clockwise to close.
Fig. 66 Draining the appliance
10.1.2 CHECKING HEAT EXCHANGER, BURNER AND
ELECTRODES
When cleaning the heat exchanger, use accessory kit consisting of brush
and extractor.
If cleaning is required:
1. Remove the air intake pipe.
2. Disconnect gas pipe from mixer unit,  Fig. 67.
3. Remove control pressure hose.
4. Rotate the mixer unit clockwise to the stop.
5. Pull the mixer unit towards you to remove.
6 720 811 922 (2014/07)
, CO and flue gas
2
Fig. 67 Removing the mixer unit
1. Disconnect the power cable and earth from the fan and the ignition
2. Unscrew locking nut for fan plate.
3. Lift and tilt the fan to the left and then pull forward to remove the fan.
Fig. 68 Fan removal
6 720 612 232-26.1O
▶ Remove electrode assembly, teaselled and gasket, inspect
▶ Remove burner.
3.
4.
5.
and flame monitoring electrode leads,  Fig. 68.
NOTICE: Burner gasket:
▶ Always re-assemble with a new burner gasket, do not
re-use the old gasket.
electrodes for corrosion and clean or replace as necessary.
Inspection/Maintenance
6 720 641 187-06.1O
41