Potterton Prima "reset button"

[elmsoft]

On the bottom of the case of my potterton boiler is a reset button. In the past it has occasionally "popped out" and needs to be pressed in again to allow the boiler to operate. Recently this has become a frequent occurence and a nuisance.
I have never understood what it is protecting- what causes it to cut out- but now I need to !
Can anyone please help?

 

[ChrisR]

It pops out if the boiler gets too hot.
That would happen if for example the pump failed. Yours might be sticking, perhaps. First thing in the morning is a typical time for that to happen.
There are other reasons, age-related, which can be hard to pin down.

 

[elmsoft]

Thank you!

So it's likely to be a circulation problem. I think the pump might be over 10 years old. Would it be a good idea to replace it anyway?

 

[kevplumb]

certainly wouldn't hurt