Potter prima b Boiler Stay on as long as it likes

[AnonymousImport]

I have recently bought a house which is about 8 years old. My boiler Potterton Prima B, comes on when supposed to and goes off when its supposed to. BUT will come back on again and stay on, thus the central heating kicks in and the house get very warm. The only way I can stop this is to turn the thermostat on the boiler down.

I have had the clock/timer replaced and the room thermostat.

Please help ???

 

[AnonymousImport]

Do you have a frost stat on your system?

 

[AnonymousImport]

Dont' think so. it is in the kitchen! With the hot water cylinder in an airing cupboard on the landing

 

[AnonymousImport]

If I turn the boiler themostat right down and leave it for a while. Turn the thermostat back to its normal position. The boiler will only kick in when the timer asks it too. But then at this point will not stay off. It keeps coming on and off with a couple of minutes in between. At this I would have to turn the thermostat on the boiler right down again.

 

[AnonymousImport]

You say that you had the timer replaced. Was this a direct replacement with the same type?
Did you have to remove the wiring? I ask because I had a similar problem, which turned out to be the wiring onto the timer being put back incorrectly. Just a suggestion.

 

[AnonymousImport]

it needed to be rewired as it was different.