Grant combi boiler. No light on CHP but programmer set to constant, no electrical power to pump, DHW light on and pump running but programmer set to off. Checked one way value on CHP and free and working. Changed programmer but fault remains, System has been operating for several years without any problems.
Grant CHP no light
- Thread starter IrishTaff
- Start date
Which model Grant combi there are several
Is dhw working normally? DHW pump running suggests a demand .
Do you have a multimeter and are competent to use it?
Is dhw working normally? DHW pump running suggests a demand .
Do you have a multimeter and are competent to use it?
If DHW pump is running heating just won't work,
DHW needs to be satisfied for ch to work.
Check if there is a feed back from flow switch they can stick open.
Also check all air valves if there is any air at all in boiler and pipework the DHW pump can run but not actually properly circulate the heat store.
DHW needs to be satisfied for ch to work.
Check if there is a feed back from flow switch they can stick open.
Also check all air valves if there is any air at all in boiler and pipework the DHW pump can run but not actually properly circulate the heat store.
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