hot water but no heating

5 Feb 2007
Reaction score
United Kingdom

Please bear with me - I'm a novice at heating - turn the dial and it comes on, (or in this case not!)

Please can you help? The radiators only get warm when I draw water and the tank refills. The electric box thingy (motorised valve?) with the lever only moves to the W setting when the water is on, the M setting when the water and heating are on and doesn't move to C setting when the heating alone is on. I can't tell if the pump is working because nothing seems to be doing anything!!

I have

ACL lifestyle mid position valve
ACL lifestyle programmer
ACl thermostat
Grundfos selectric pump

I'm sorry I can't see anymore details than that.

If I need to replace, are ACL still in existence?

thanks in anticipation

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Can you hear the room thermostat click whilst being rotated, should do if it has a negative feed.

ACL is Drayton.
Thanks Gasman

Yes, the thermostat click when I move it but the boiler doesn't fire up as it usually does. (I usually run the heating on constant.) The boiler now only fires up if I've drawn hot water, the heating comes on too, then. Thermostat's clicking at about 15!

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From what you say, the problem appears to be the motor within your 3 port valve. To get heating, the valve must move across to allow the water to flow and also it must trigger a microswitch to fire up the boiler.
If you run off some hot water, the demand will be for both HW and CH.
Because HW is demanded the boiler does not depend on the microswitch, it gets its supply from the cylinder stat.
I had the same problem, but in my case the motor was ok and it did move across but the microswitch had failed.
:rolleyes: :rolleyes: :rolleyes:

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