Boiler cutting out

[championpd]

I have a 8-year old Potterton wall hung PrimaF, regularly serviced.  Very occasionally (but often enough to be infuriating!) it needs resetting.

The latest occurence may yield a clue.  I had also switched on the immersion heater element, as I needed rapid re-heat with a house-full of people.  I left the immersion on and during the day the boiler tripped out. 

Could this be because when the boiler tried to start it was surprised to find the water, either in the HW tank, or the bit of CH water in the HW tank's coils, already very hot?

Any advice/suggestions to try welcome.

Peter

 

[BillyNoMates]

This is the boiler with the rest button underneath in a small finger-sized opening ?

I would think the thermal cutout is going out of spec with age. It takes a lot to get it to trip I.e. no water in the boiler or serious airlocks - both unlikely from what you describe. If you have the manual with detailed diagram, replacement is relatively simple and the part relatively inexpensive.