Hot Rads Only When Calling For Hot Water

[Mr. Tickle]

Hello Board!

I've had a few problems with our CH and HW systems over the last 2 years...We have an open system, Cold storage in loft, indirect tank in cupbaord, expansion feed tank in loft, 'T' valve etc.

The rads only come on when the thermostat on the tank is calling for heat. When the stat in the living room is calling for heat, the programmer is calling for heat, nothing happens. If i move the stat on the tank up higher, it comes on, valve turns, pump pumps, boiler fires, heat ensues.

This has just started to happen in the last few days. But sometimes the rads work fine...

If you guys and gals have any suggestions, i'd be greatly appreciative.

Cheers,

Mr. Tickle.

 

[hi-spec plumbing heating]

sounds like you have a sticky motorised valve.

 

[Mr. Tickle]

Hi,

Thanks for your diagnosis.

Would the manual lever be stuck itself, or would it flop around?

Last time this happened, the lever was stuck so hard it would not move. We had the motor on the valve replaced and it worked fine.

But this time, it is a little different. The valve moves around happily when required.

Thanks,

Mr. T.

 

[hi-spec plumbing heating]

may not be making the micro swith when heating called for.

 

[Mr. Tickle]

Sorry, the lever is turned by a motor which hits a microswitch that fires the boiler?

 

[hi-spec plumbing heating]

is it a honeywell valve?

 

[Mr. Tickle]

Yes - it is Honeywell

 

[hi-spec plumbing heating]

turn hw off and just put heating on check see if you have 230v at white and grey wires and orange

 

[Mr. Tickle]

OK, 230v over White and Grey and 230v over White and Orange? This is the motorised part of the valve, the stepper motor, yes?

Thanks again.

 

[hi-spec plumbing heating]

you checked in your wiring centre. if you have 230v at each of them colours your boiler and pump should work

 

[Mr. Tickle]

so i need 230v over the:

White
Grey

and

Orange

wires? Do i just put the other probe to earth?

 

[hi-spec plumbing heating]

ya stick it in earth then the other in white 230v then check grey 230v then orange 230v.
tell me what has power and what don't from the 3 checks.