Help on central heating motorised valve wiring

[Stevehobbs]

If you disconnect the orange wire at the wiring centre ( isolate it in an insulated terminal block) and test voltage on white wire ,if it still reads 230/240 volts with programmer set only for domestic hot water ,the issue is not within the actuator.

Got it perfect Terry thank you, will update you tomorrow

 

[ericmark]

The default setting is domestic hot water, no power comes from the valve when using the boiler for DHW but the orange wire will become live, but that's a back feed.

I remember doing it in my daughters old house and the micro switches had failed and I was getting all sorts of odd reading due to those internal diodes and resistors.

 

[terryplumb]

Was the programmer newly installed ? I don't follow why you need to run a seperate wire from it ?

 

[Stevehobbs]

If you disconnect the orange wire at the wiring centre ( isolate it in an insulated terminal block) and test voltage on white wire ,if it still reads 230/240 volts with programmer set only for domestic hot water ,the issue is not within the actuator.

Hi Terry
dont know if you got previous reply, sounds logical will let you know how I get on tomorrow Thanks Steve

 

[Stevehobbs]

The default setting is domestic hot water, no power comes from the valve when using the boiler for DHW but the orange wire will become live, but that's a back feed.

I remember doing it in my daughters old house and the micro switches had failed and I was getting all sorts of odd reading due to those internal diodes and resistors.

Think you are right but annoying thing is that it is 4 weeks old……

 

[terryplumb]

Was the programmer newly installed ? I don't follow why you need to run a seperate wire from it ?

?????

 

[Stevehobbs]

Was the programmer newly installed ? I don't follow why you need to run a seperate wire from it ?

No Terry it’s an old programmer , it has a wire connected to HW off but I cannot find the other end of it in the airing cupboard anywhere. There was no wire from HW off connected to terminal 2 on cylinder stat and grey wire on valve so looks as if somehow I have to get a wire from programmer to upstairs cupboard which is annoying but cannot find other end anywhere, maybe I’ll find it in attic tomorrow…

 

[terryplumb]

Seems there is more going on than I first thought. How did the system work before recent work was done ? Besides a new boiler and MPV , has any wiring been changed at wiring centre ?

 

[Stevehobbs]

Seems there is more going on than I first thought. How did the system work before recent work was done ?

To be honest boiler is less than 12 months old, I don’t see how engineer ever had it working properly and old tenants never complained, new tenants in and they complained not working so here we are. He is on holiday, he says there’s an electrical fault but he doesn’t do electrics , he says he replaced 3 port but I am thinking he didn’t change motor head but there’s an old one in cupboard. So thought I’d print diagram and look myself and what you now know is what I’ve found all other circuitry checks out but there was never a HW off wire connected

 

[terryplumb]

What exactly did tenant report that wasn't working ?

 

[Stevehobbs]

What exactly did tenant report that wasn't working ?

From what I remember I think they could get heating only but not water and heating but maybe wrong, not sure sorry.
I am confident all wires from programmer 3 and 4 and wires to and from stats are good as I have checked re-checked that’s how I found no HW off signal and the rogue 240v on white when HW calling.
I think I need a new heating engineer because I cannot relate to a heating engineer that doesn’t understand circuitry and needs to call in an electrician. do you by any chance know if the Corgi 3 port head from Toolstation is compatible with the 4073a ?

 

[terryplumb]

I very much doubt the corgi actuator will be compatible with the Honeywell brass body .
You mentioned that there are unidentified live wires , I assume at the wiring centre, could one be the hot water off from programmer ?

 

[Stevehobbs]

I very much doubt the corgi actuator will be compatible with the Honeywell brass body .
You mentioned that there are unidentified live wires , I assume at the wiring centre, could one be the hot water off from programmer ?

Unfortunately not I ran a cable from terminal 1 HW off with power off up the stairs to airing cupboard and did continuity check on every wire and could not locate other end. I don’t know what these wires are it is a red and yellow in a block that only go to 240v when heating calls which seems strange?

 

[Stevehobbs]

Unfortunately not I ran a cable from terminal 1 HW off with power off up the stairs to airing cupboard and did continuity check on every wire and could not locate other end. I don’t know what these wires are it is a red and yellow in a block that only go to 240v when heating calls which seems strange?

Sorry maybe wrong would need to double check , I think they get 240v on activation of heating on not demand

 

[Stevehobbs]

Sorry maybe wrong would need to double check , I think they get 240v on activation of heating on not demand

Sorry maybe wrong would need to double check , I think they get 240v on activation of heating on not demand

perhaps roomstat used to be upstairs