Replacement Of Parts; Pcb Control Board And Transformer - Worcester GREENSTAR HE combi Series Installation And Servicing Instructions

Heating system pressure
Fill the system using the WRc approved
i
filling loop.
B The pointer on the pressure gauge should be 1 bar.
B If the pointer is below 1 bar (when the system is
cold), water should be added until the pointer is
1 bar again.
B Max. pressure of 2.5 bar when the heating system
water is at maximum temperature must not be
exceeded. If this pressure is exceeded then an extra
expansion vessel must be fitted in the system return
as close to the appliance as possible.
B If the system does not retain the pressure, the expan-
sion vessel and the heating system should be
checked for leaks.
Electrical wiring
B Check the electrical wiring for physical damage and
replace any damaged wires.
6 720 610 576 GB (03.02)
8.3

Replacement of Parts

Before changing any components check that the gas is
turned off and that the appliance is electrically isolated.
When necessary close the system valves and drain the
appliance.
Refitting is a reverse of the procedure for removal using
new seals or o-rings as appropriate.
8.3.1

PCB control board and transformer

B Switch off the appliance.
B Disconnect appliance from the power supply.
B Unplug all connectors from the control box (inc.
keyed plug). Access is gained by removing the
covers. Refer to fig. 25, 26.
B Remove screw holding power connector earth lead
and remove earth lead.
B Remove two top fixing screws from the control box.
Refer to fig. 59.
Fig. 59
B Lower the control box.
B Unscrew earth lead.
B Unscrew four fixing screws from cover plate. Refer to
fig. 60.
B Prise off cover plate.
B Pull off transformer.
B Remove pcb holder.
Maintenance
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