Drayton Wiser Install - Wiring help

[smiff1985]

Hi - new here!

Bought a Drayton Wiser multizone Kit 1 for my system in an Amazon sale. Want to try out smart heating. Without further ado:

Current setup
Boiler:Ideal logic ESP1 30
Altech programmable thermostat / Salus RT500
Honeywell V4043 zone valve

Each room stat is battery powered and has L and LS.

The wiser install needs mains power from the instructions. There's a 3 core & earth running to each room stat (grey has been sheathed and terminated at the wall plate with earth). Live (brown) and LS (black) are hooked up.

Proposed setup:

Wiser wall plate is standard N L 1 2 3 4

- Connect current L to L
- repurpose grey to N and move to neutral in the wiring centre
- LS black to 3
- loop L to 1.

My main question is around the last point. Can I loop L to 1 at the wall plate? The Drayton manual seems to suggest that. If so, I'd look to do that with a small section of 1mm2 of fixed wiring (just brown core) that's going spare in my kit.

If not, would I need to loop at the wiring centre instead? That would require a 4 core and earth to be run in place of current 3 core and earth. Sound right?

Attached pics of wiring centre and current wall plate.

Any help confirming the above would be much appreciated.

I'm wiring diagram 1 (for single zone). I will upgrade the second zone if this goes well and I like the system.

And now I've just seen this thread where someone has looped as I discussed above. I searched 5 posts without spotting this relevant one...

https://www.diynot.com/diy/threads/...doesnt-seem-to-be-switching-on-boiler.532005/

So it sounds feasible that I can do as I propose?

 

[stem]

You have a multi zone system, so the room thermostats will be controlling motorised valves, rather than the boiler (the motorised valves then control the boiler) the other post you refer to is a single zone without motorised valves, so the wiser is wired directly to the boiler. It's a different type of installation from yours.

However, what you have posted sounds reasonable to me.

Looking at the picture of the thermostat you have posted, the two switching wires need to be redirected to the wiser. The brown wire now in L goes to the wiser (1) COM. the black wire now in SL goes to the wiser (3) ON. I assume you have the 'One Channel' version.

You can do this either by rerouting the existing cable from the thermostat to the wiser, or finding the other end of it at the wiring centre, removing the existing cable and running a new one from there to the wiser. That's the switching sorted, so now you need a mains supply to the wiser N & L

As you have figured, if you link the wiser (1) COM which already has a live in, to the wiser (L) that's the live sorted.

For the neutral, that can be picked up from the wiring centre. Unfortunately, I can't follow the wires in your photo of the wiring centre clearly, so follow the blue wires from the motorised valves to see where they are connected and you can use that, it looks like here, but check:

If you decide to use the existing thermostat cable, and the grey wire at the existing thermostat and presently parked in the earth terminal can be re-purposed as the neutral to connect the Wiser N to the wiring centre N then that's fine. Put a blue sleeve over it at both ends to show it's now being used as neutral.

 

[smiff1985]

Thanks for the detailed post.

Yeah, if I repurposed the grey, I'd planned to sleeve it.

One of the greys at the top of the wiring centre pic is currently linked to the stat, so I'd disconnect from there and hook into where the neutral for the valve is connected down at the bottom.

I guess my question was about whether I can do as the other person did on the other post and loop L and 1 at the plate using a short brown wire. Is that allowed? I wasn't suggesting following his plan but I also wasn't clear.

The other option would be to run a 4C+Earth which I can do but just a faff. I've already worked out most of the connections at the wiring centre... I wish they had used a Honeywell standard S plan plus 10 way but ho hum - the motorised valve wires made it fairly easy to identify the other ports by logic.

 

[stem]

I guess my question was about whether I can do as the other person did on the other post and loop L and 1 at the plate using a short brown wire. Is that allowed? I wasn't suggesting following his plan but I also wasn't clear.

Yes you can. Most of the One Channel Wiser's are connected like that, it's even shown in their diagram.

It's shown dashed, because it's an option & not always required. As you have realised sometimes a 4 core cable is used instead, and some boilers are wired to have 24v control so 1 and COM would have to be kept separate from the 230V supply then anyway.

 

[smiff1985]

You've been a star, thanks. I'll hook it all up tonight.

Is it worth using the OpenTherm module?

My boiler supports it but I'd have to get a GS engineer to do that as it looks like it would require opening the case which I think I'm not permitted under the regs from doing. Just want to weigh up cost/benefit of doing so.

 

[stem]

In theory OT regulates the boiler more accurately rather than just switching it 'on' and 'off' in order to achieve some energy savings. Although I have yet to find anyone that can quantify the savings.

The problem you have, is that your system is zoned and fitted with motorised valves and it is they that switch the boiler on and off, and not the thermostat. So in your case you can't use it.

 

[smiff1985]

Ah, well that's solved that issue. Thanks again. I don't really know how the modulation works in OT - haven't looked into it yet. Just saw it in the manual for both boiler and smart kit so thought I'd ask.

Makes sense. Thanks again.