Central heating midport valve or wiring problems

[ratmanuk]

Morning All After bit of advice

We were due a wireless thermostat fitting by a (unnamed company )
due to how my system is they could not wire it in needed a live feed

After they went things were not right after they had poked around . boiler would not fire

My dads a sparky although works on industrial machinery when we opened up we found the grey wire was loose we have now fitted it to the correct connector or so we think . my dads offered to come back and have another look but he works alot and has no time at the minute .

The boiler fires

But symptoms are if the boiler fires for HW all is fine . if CH comes on the valve moves to CH and stays there will not move to mid position or back to HW .


So if the cylinder stat calls the boiler fires but it just heats the radiators due to the three port valve stuck over in CH

If turn the system off three port valve returns to HW
position

Any ideas?

[/URL][/IMG] here the photo of the wiring box for the System house has built 1996

[/URL][/IMG]

 

[hertsboilers]

Wrong wiring. Was the system working properly before the wireless stat fitted in?

 

[ratmanuk]

Yes it was but the CH was has not been used since march
Just to confirm the wireless stat has not been fitted . system is as was

Only thing that changed is the grey wire if we didn't put it back right .

 

[picasso]

From what I can see the grey wire is correct although it really needs someone on site to confirm.

 

[bernardgreen]

Is that a Green/Yellow being used for something other than Earth

If it is then replace that cable with four core ( or five core ) and use the Green/Yellow for Earth. Do that even if the item at the far end does not need the Earth

 

[ratmanuk]

The white cable you can see there is the cylinder stat

 

[FiremanT]

The grey should connrect to the "HW OFF". Google for Y Plan diagram

 

[Dan Robinson]

Bernard is right (strictly speaking). Looks like the earth wire is being used for HW Off.

If the cylinder is not in the same space as the junction box - I.e. you can see the full length of the flex in the same room/cupboard - then you should change the flex to 3&e.

 

[ratmanuk]

The cylinder is right next to me in this pic . So do i need a plumber or a electrician ? to come sort this out ? anyone to recommend Leeds/Wakefield Area ?

 

[Dan Robinson]

You need a heating engineer that can understand a Y plan, which is hardly complicated.

Most electricians haven't got a clue.

 

[EFLImpudence]

Most electricians haven't got a clue.

Oi.
You're probably right.

You need a heating engineer that can understand a Y plan, which is hardly complicated.

That implies that some don't.

It took me five "heating engineers" to get a boiler repaired - very simple in the end.



I was going to say the OP needs someone who can read a wiring diagram and a Dad who's an electrician may be good but …

 

[Dan Robinson]

I did say you need one that understands a Y plan .

 

[Steelmasons]

At a guess I would say the earth core from cylinder stat is hot water 'off' , remove grey core from terminal block and terminate into block with earth/black , see if it works..

If you can take a photo of the cables entering the box then you will get a confirmed answer........or simply remove programmer and post which colour core terminates @ 'HW OFF'.

 

[ratmanuk]

Ok i have taken some pics just to make sure but it looks like your Right Black wire is hw off

i just need to change over grey wire to black/earth terminal on block ?

 

[Steelmasons]

There you go , easy ain't it..

Donate £60 to your chosen charity , post receipt please.