Constant hot water temperature regardless of temp. setting

[masnick]

Hi,

I have a Halstead Best 60 wall-hung gas boiler. The central heating is pumped and the DHW is gravity fed.

When running normally, the water temperature of both the CH and DHW remains at 50 C regardless of the temperature setting on the front of the boiler.

I'm wondering if the thermistor is not operating properly?

Does anyone have any advice on what could be wrong?

Thanks,

Mike

 

[ChrisR]

Are you sure the knob is turning the shaft? If so, does the boiler go on and off when it's at its running temp and you turn the knob up and down?

I have a full set of spares for this boiler - spare boiler in fact - so could measure the resistance . Also it could be the potentiometer track cracked. Depends how handy you are with a meter... The pot is a cheap spare.