Wiring for old Drayton LP111

[DPJ]

Hi, am after some advice about next steps in replacing our old Drayton LP111 - hoped it would be a simple change the controller but keep the same wiring, but on inspection I wonder if it's more complicated.

The controller is connected to an old Vaillant Ecomax 236, but the wiring isn't what I expected. I was expecting the mains supply to go into the boiler, then from there to the controller, but it goes into the controller first, then to the boiler (see photo of the wiring on the controller base plate). It's all off the same fused spur, so both boiler and controller can be isolated on one switch.

Am I right in my assumption? And if so, would it be a case of getting someone out to re-order so the live goes to the boiler, then from there to the controller? Or is there a way to just get a new controller (was going for Honeywell T4r) and using the existing wiring?

Many thanks for any advice.

 

[CBW]

In my opinion, you could keep it the same, because you end up piggybacking from the boiler l-n-e anyway. Not sure if this is correct, and you can change it if you wish.

 

[DPJ]

Thanks Chris,
If I did piggyback, would I have a problem fitting both wires into the new terminals - is there a standard way to do this? I put in a T4 for my mum a while ago (feed came from boiler on that set up) and the terminals didn't look big enough to take 2 wires.

 

[CBW]

If you piggybacked there could be an issue with terminals. Sometimes terminals are big enough to take 2 wires, but this is where you use a wago connector or terminal block.

 

[stem]

When space is tight, I normally sink a single backbox into the wall behind; terminate the wires in there and then only bring those that are needed through into the programmer. If you do go this route and use a metal backbox, don't forget to make an earth connection to it.