HELP. hot water only works when heating is on!!!!

[Tracy Graham]

Please help....I have a Potterton boiler and everything is fine apart from the tap icon has a yellow light at the mo, all the rest are red or green. The hot water will only heat up if the central heating is on.Why is this. Is there something simple I can do to fix it?

Edit: Sorry 30 HE

 

[45yearsagasman]

What Potterton? They made dozens of models.

 

[ianmcd]

if you can not see which model you have take a photo of it and post it and we will be able to help you

 

[45yearsagasman]

If I recall correctly, your model has a pressure differential valve which operates when the hot tap is operated. It could be the internal diaphragm has failed and is not operating the micro switch to bring on hot water. This involves a visual inspection together with a few electrical tests to confirm. If it is the diaphragm then it's a cheap simple fix. Wether you can do it is not for me to say, but a repair will not cost a fortune. At the most it would be 45 mins work for a pro.