Help with heating controls

[jake987]

Hi,
I have rather stupidly attempted to change my heating control unit in the airing cupboard, due to previous unit repeatedly resetting itself for no reason.
Now I have fitted the new unit, even with water and heating both off on the unit, the heating runs continuously. The thermostate downstairs with the temperature on clicks on and off like usual when setting a temperature. However, the boiler does not react to this. Heating stays on even when above the temperature on the wall.

Any help greatly received. Iv even tried refitting old heating control unit, with the wiring identical and heating still runs continuously

Pics of wiring below and airing cupboard set up. Old unit was channel plus XL, nlh27

 

[RandomGrinch]

...and your new heating controller is a ???

 

[jake987]

I tried a Drayton lp822, but this didn't work.
I have now ordered a horstmann h27 XL to keep the wiring the same as old unit?

 

[RandomGrinch]

I presume ...155427.jpg is the before picture, and ...204515.jpg is the after?

The wiring 'appears' identical in both.

...and when you replace the Channel Plus on the backplate, the heating runs continuously.
Does it continue to run with the Channel Plus removed from the backplate?

 

[jake987]

That's correct 427 was original, 515 my handywork.
Iv checked and checked and it seems iv wired it in correct order to me, but happy to be corrected.

That is correct when channel plus refitted heating runs continuously, irrelevant of what I set the thermostat too downstairs. This does click on/off like usual but makes no difference.

I haven't tried it without the channel plus in place. Will try this at lunch and come back to you.

 

[Johntheo5]

I tried a Drayton lp822, but this didn't work.
I have now ordered a horstmann h27 XL to keep the wiring the same as old unit?

Took this from the Drayton LP822 instruction.

 

[jake987]

Yeah that's what I tried but the heating stayed on with that too

 

[Johntheo5]

Horstmann, Is this wiring the same as your old one?

 

[jake987]

I think it's like this. But without the frost bit. Sorry if I'm not clear, new to this.

 

[jake987]

I presume ...155427.jpg is the before picture, and ...204515.jpg is the after?

The wiring 'appears' identical in both.

...and when you replace the Channel Plus on the backplate, the heating runs continuously.
Does it continue to run with the Channel Plus removed from the backplate?

Just checked and yes as soon as I turn on the fused switch. Even tho the channel plus isn't there. Just the back plate. Everything fires.

 

[RandomGrinch]

Just checked and yes as soon as I turn on the fused switch. Even tho the channel plus isn't there. Just the back plate. Everything fires.

You may have disturbed some wiring in the wiring centre, but there is also the possibility of a valve being stuck open, etc.
I'm afraid some further investigation may be necessary.
At least your wiring (possibly) wasn't to blame!

 

[jake987]

I will check wiring to make sure nothing has come loose etc.
Is their anyway I would be able to tell if it's the valve? The switch on the valve seems to move very easily, but iv never tried it before so don't know if it's always been like that

 

[jake987]

This is the valve. There is no resistance on the switch at all. I can slide it freely when the power is on and off. The switch stays in the position I leave it. Is that normal or should it be dragging itself back?

 

[RandomGrinch]

This is the valve. There is no resistance on the switch at all. I can slide it freely when the power is on and off. The switch stays in the position I leave it. Is that normal or should it be dragging itself back?

I'm afraid my only experience with zone valves has been through this forum. Hopefully there will be an expert along soon

What I can say, is if you can follow the cable from the valve, back to the wiring centre, you should see an orange and a grey wire coming from the cable.
If you temporarily disconnect one of these wires from the wiring centre, and the heating stays off, you have probably located the fault.

If you have a multimeter, that would also be very handy for troubleshooting!

 

[ianmcd]

In your pic you show a Dual channel ACL programmer but on the wiring of the back plate you have wired links, the ACL doesnt use external links that is why it wont go off