I have a camray quartet oil fired boiler.
The thermostat relay on the wall keeps clicking. If the boiler should be off it will switch it on for a short time (15 - 30 seconds) then go off. This repeats once or twice then settles down.
I thought it might be a faulty thermostat so replaced that. But still have the same problem.
Last night I noticed on the LCD control panel (which I think was optional on this model) that the HW and CH lights came on when the clicking noise occurred and then went off after the 15 - 30 seconds time.
Not sure what to change next?