hw very hot when ch selected

28 Jan 2008
Reaction score
United Kingdom
When my central heating is on, I have loads of hot water aswell (even though I haven't requested hw, and it is turned off at the timer). The actuator valve has been replaced on the hw, but doesn't seem to have made a difference. Tank thermostat appears to be working ok and controls hw temperature, but if ch is on then the water temp is boiling.

Have a potterton promax condensing boiler. The condensate drain from it is leaking. Could this be messing something up in the boiler itself?? Please help.
Sponsored Links
How many "Actuator valves" do you have.

A leaking condense waste wont affect operation you describe.
I have three. one hw and two central heating - one controls upstairs and one down
When the HW zone valve was changed was it the whole thing or just the head.
Sponsored Links
First time the head, second time think he did the whole thing as he drained the system.
Better if you knew he had actually changed it.

Sounds like it is stuck open. slide the lever over to the manual position and see if it motors back.

You will need your man back otherwise.
its definitely changed as it is a different model.
You have crossed wires then in the wiring centre, and it must of been like this from install is all I can think of without seeing it. sorry

think you may be right as I reckon the hot water has ALWAYS been too hot, and no one has solved the problem yet. Thanks for your time.
no sorry. but if you could give advice then I could pass on to plumber friend who might be able to help.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links