Heating switching on regardless

[EddieB]

I have a Fully pumped S plan with two zone valves HW & CH, when the programmer is off, the room stat is turned down as far as it will go the heating still comes on, I'm assuming the CH 2 port valve is faulty and must be letting voltage through to the pump/ boiler. I have two valves a drayton ZA5 and an unidentifiable Range, if it is a faulty valve can I just remove the body and leave the base in place, has anybody else experienced this issue before and confirm my thought regarding the faulty valve? Cheers

 

[telectrix]

get your meter out first and see where the trigger voltage is coming from.

 

[Wilko]

Maybe orange lead from CH valve is now permanently live. But don't buy anything till it's proven what's wrong as Tel has said.

 

[buzzlightyear]

[/ATTACH] there you go, follow the wiring diagram.it could be the controller needs changing. Are you falimarised with heating systems.

 

[sean_ork]

Dead test the valves microswitch first

 

[Leesparkykent]

put programner and thermostat in the off positions for both heating and hot water, separate the oranges of both valves, test which orange has voltage, once you've confirmed which one has voltage check if there is voltage on the brown of the same valve. If there is no voltage on the brown but voltage on the orange then the micro switch is stuck closed between grey and orange.

I doubt it's the programmer as the thermostat would have to also be faulty as they are in series.

Double check the CH valve isn't manually open as some valves have this facility. If the valve isn't seized open then you could get a replacement head as the micro switch is stuck. If the valve is seized then you will need a plumber to replace it.

 

[Devonchris]

Also check you haven't got a frost stat somewhere that's turned up higher than normal or faulty.

 

[EddieB]

Guys
All sorted it turns out the micro switch on the Heating Valve was sticking ( Grey & Orange) I operated the valve a couple of times and hey Presto it now works.
Thank you to all of you who responded .

 

[EddieB]

get your meter out first and see where the trigger voltage is coming from.

Ah the trusty meter all now sorted thank you

 

[EddieB]

put programner and thermostat in the off positions for both heating and hot water, separate the oranges of both valves, test which orange has voltage, once you've confirmed which one has voltage check if there is voltage on the brown of the same valve. If there is no voltage on the brown but voltage on the orange then the micro switch is stuck closed between grey and orange.

I doubt it's the programmer as the thermostat would have to also be faulty as they are in series.

Double check the CH valve isn't manually open as some valves have this facility. If the valve isn't seized open then you could get a replacement head as the micro switch is stuck. If the valve is seized then you will need a plumber to replace it.

All sorted, thank you for your response

 

[EddieB]

Maybe orange lead from CH valve is now permanently live. But don't buy anything till it's proven what's wrong as Tel has said.

So it proved, thanks for the response

 

[Devonchris]

Good well done. Thanks for the update.

 

[Leesparkykent]

Just warn the customer they maybe looking at a replacement soon as no doubt it will stick again in the near future.

 

[buzzlightyear]

if faulty is easy to replace, has long you have shut of valves near it .but I if I was you
I would get a plumber in having to drain down and put in central heating additive
like fornix inhibitor .if you replace it you will be back within the 12months.

 

[Wilko]

I had one similar this morning - this time CH wouldn't turn on. The wiring centre was a copy of @Leesparkykent avatar ...