Potterton Profile 40e hotwater blues...

[Qjames]

I've recently moved house and got a problem with my hotwater heating. The 3 port valve will not switch to the hot water circuit and I'm pulling my hair out over it.
I've checked every component (other than the boiler) and they are all individually functioning correctly (cylinder stat, V4047, programmer, CM67 etc.). I thought it was the messy junction box, but I've re-wired everything with a Honeywell Idiots wiring box and still no joy. It will happily heat the house all day long but ignores all requests for hotwater.

This brings me round to question the boiler. Any ideas?

 

[GasAid]

The valve should rest in the hot water position... If you are sure you have no voltage going to the valve except the switch line (Not fitted on all valves); then it's the valve itself that's knackered and needs replacing as it's got jammed.

 

[Qjames]

The valve was replaced about 2 months ago as it was thought that this was the cause of the problem. So unless i've got a dodgy one...

If I turn the CH off and ask for HW then the valve moves and the CH comes on. I can hear the valve move back to the HW open position when I switch everything off.

 

[GasAid]

You'll need an electrical test meter to diagnose this further; I would suggest that something is not wired correctly; or; something is sending the wrong signal; such as a faulty clock... But a leccy meter is required.