DIY Doctor UK DIY Forums

I've got a strange problem with my Potterton 80e.

The boiler fires up ok on heating, but on hot water demand the boiler starts to fire up and then switches off. It cycles like this for a while i.e tries to fireup-->turns off-->tries to fireup-->turns off before eventually firing up ok. Once it has started everything seems to work fine but it repeats the above cycle several times during operation.

Would anybody be able to tell me what is causing this.

Could be a faulty DHW flow switch or microswitch.

Does it work ok on CH ? this would rule out an ignition problem.

htg

Central heating fires up ok as soon as you switch it on.

DHW will fire up eventually, it just has goes through a on/off cycle several times before it ignites.

Not sure if it is a main PCB fault, that s what plumber diagnosed over phone when I explained symptoms. Not convinced though.

Hi i would think its more like a diaphram problem in the domestic part of the valve they are prone to getting shredded anmd worn out ther is a micro switch on the end that closes when calling for water but if the diphram is faulty it will take a couple of times before enough pressure builds up behind it i would say the p c b is ok as the boiler is functioning ok on the heating

mick