gloworm swiftflow

[simon20569]

i have a gloworm swiftflow combie boiler hot water works fine but central heating fires up and then goes off after 30 seconds thermister has been changed still the same problem any ideas? the boilers a swiftflow75e

 

[andsam]

Check all rads are open and the isloation valves under the boiler are open. The pump only works for ch and not hot water so the pump could be stuck. If this is the case I would think the boiler would be noisey and the pilot would go out.