Hi

I have a Baxi Bermuda boiler and, after it has been on for about an
hour, the bathroom radiator has been getting very hot. It is the only
radiator without a thermostat.
I turn the thermostat, mounted on the boiler, down to LOW but still
the radiators are too hot.
There are no other problems with the system and the temporary solution
is just to switch the heating off for a while till things cool down.
There is no knocking sound to indicate a faulty pump etc.

I'm guessing that the boiler thermostat is faulty. Is there any way
that I can test it? Is it easy to replace?

thanks for your help
Nigel