Wiring guidance - Replacing existing controller and receiver with Hive

[ZeroTools]

Hi all,

I am looking to replace my existing British Gas UP2 controller and Drayton wireless thermostat with a Hive v2. I was hoping it would be a simple swap over of the UP2 and disconnection of the drayton receiver, but my wiring is a bit convaluted and some of the connections aren't as I was expecting. Can anyone offer some advice on rewiring what I have in the photos? Ideally I'd like to leave the UP2 in-situ to cover up the missing tile as both it and the Drayton receiver have a Hive compatible backplate, but I'm guessing it would be a lot easier to replace the UP2 with the Hive receiver and just disconnect the Drayton one. I have a conventional boiler (glow worm flexicom 18hx) and HW system.

Any advice greatfully received.

 

[flameport]

Disconnect power.
On the UP2 plate on the right, remove all 5 wires which go to the Drayton plate. Any other wires already in the terminals must stay in there exactly as they are now.
The red wire previously connected to grey in that individual connector goes into terminal 4 on the backplate.
The Hive piece fits onto the same backplate that the UP2 did.
The Drayton backplate and the mess attached to it are removed.
The tiles will need some repair.

 

[ZeroTools]

Thanks very much! Just out of curiosity, why is there no connection to terminal 2 (heating off)?

 

[flameport]

Most systems do not require heating off or HW off. The valves are usually powered to open and an internal spring to close, so just removing power is good enough for off.

Yours is probably a Y plan with a single 3 position valve which requires a HW off to indicate that heating only is required.

Some valves were made which required power to both open and close, those would require all 4 terminals. They are rarely found in domestic heating systems.