Hi, hoping for some help! I believe I have a system boiler, I have a hot water cylinder in the loft and the boiler only has on/off and temp dials!

We have been experiencing some problems with it whereby it either won’t come on or when it’s on it won’t go off! The only way we can get it to turn off is by switching the boiler off.

I recently got someone out to service it and mentioned this to him and he told me that there was nothing wrong with the boiler and he advised that if the issue continues to happen then it’s more than likely the thermostat.

I’m no expert but I’m not 100% convinced because when we turn the dial on the thermostat it clicks to turn on at around the temperature I expect it to be. Maybe I’m wrong but if the thermostat was broken surely it wouldn’t click at the right place?? Or would it??

I just don’t want to waste money on a new thermostat if it’s not going to fix the problem.

Thanks!