Potterton Prima won't switch off!

[wills100]

Hi,

I trying to figure why a Potterton Prima 60F keeps firing up even when the room stat is down and the timeclock is set to off for both HW and CH. When everything is off, the gas valve solenoids are still getting driven from the circuit board. It's a bit concerning, has anybody heard of this before on these boilers?

Thanks in advance!

Will.

 

[gstens baxi]

This could be due to the micro switch/s in the diverter valve/s sticking in the on position.

 

[Nexus6]

I have exactly the same problem with my Potterton Profile 60e boiler. with the timer set to off and the termostat set low sometimes the boiler fires up. This is particularly annoying in the middle of the night as all the radiators get hot. I had a service engineer pay a visit and after speaking to Potterton he also concluded that the problem was the micro-switches on the automatic values. I haven't had my replaced yet as the cost was too high for my liking. However, as a temporary measure turning the power off on the timer switches off the boiler at night. My next job is to lubricat ethe micro-switches with contact cleaner.

 

[gstens baxi]

Just read your problem again. Just wondering if you have a frost stat as this can keep the boiler on when it is very cold. If so a pipe stat would cure the problem.