hw very hot when ch selected

[pamzer]

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.

 

[clf-gas]

How many "Actuator valves" do you have.

A leaking condense waste wont affect operation you describe.

 

[pamzer]

I have three. one hw and two central heating - one controls upstairs and one down

 

[clf-gas]

When the HW zone valve was changed was it the whole thing or just the head.

 

[pamzer]

First time the head, second time think he did the whole thing as he drained the system.

 

[clf-gas]

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.

 

[pamzer]

its definitely changed as it is a different model.

 

[clf-gas]

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

 

[pamzer]

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.

 

[clf-gas]

Are you competent with wiring.

 

[pamzer]

no sorry. but if you could give advice then I could pass on to plumber friend who might be able to help.

 

[clf-gas]

Click on this then and have a look in the blue section, yours is more than likely wired as the 'S' plan.

Use the zoom to see clearly Sorry.(teaching you to suck lemons I know)

http://www.tlc-direct.co.uk/Technical/DataSheets/Horstmann/Pics.pdf


Fairly typical wiring of heating system controls.