Central Heating boiler goes into start up shut down loop?
Ravenheat CSI 85 A(T) about 4 years old.
Boiler pump starts, boiler fires up, runs a few seconds then shuts down.
Appears to react to room control stat, as when I turn the stat down to 10C the boiler does not start at all, as you would expect.
When required for hot water only boiler runs fine.
Any ideas?