Combi 80 Boiler stop/start ??

[johngm]

Hi all, I have a problem with my potterton combi 80 boiler. the problem is, when the heating fires up, the boiler only comes on for a couple of mins then stops for a couple of mins, then starts again and so on. It dosent cut out, just stop/ start, and as you can guess, because of this, takes ages for the house to warm up. Pressure seems OK (about 1Bar cold). Any Ideas ?

Kind regards John

 

[powell30]

Thermistor?
Pump?
Board?

 

[Baxmax]

A.P.S Tube split.....

 

[johngm]

I Changed the pump recently as this was knackered, but i will check the board again for dry joints (had to do some re-soldering on this a couple of years ago). I will check the tube also. Thanks for the suggestions. I will check out over the weekend and let you know how i got on.

Cheers