BG thermostat re-wire to HIVE active 2 channel

[unknovvn]

We had this old British Gas central heating thermostat

which has the following wiring:

I thought it was going to be straight forward to wire it but doesn’t seem like it.
Looking at the wiring diagram for the dual channel I am missing a cable

Any suggestion?

 

[stem]

Hive is a British Gas product, but the diagram of Hive you have shown is the Dual Channel version for systems with stored hot water (aka a hot water cylinder).

A direct replacement for the old BG thermostat that you have would be the Single Channel Version of Hive as below. It should fit straight onto the existing backplate without the need to move any wiring. Your system doesn't use the heating off connection, (terminal 2) but don't worry, no one else does either.

So either you have the wrong version of Hive, or you have the right version of Hive but have posted the wrong diagram. The single channel version just has one light and button at the bottom.

 

[unknovvn]

So...
I’ve got the right hive version for hot water cylinder.
I managed to find the wiring diagram for the old BG thermostat, from there I worked out what cable’s what. Wasn’t sure if the white wire was for the central heating.
Also, just like you said there was no wire to connect to CH OFF.

 

[stem]

So...I’ve got the right hive version for hot water cylinder.

So are you saying that you do have a hot water cylinder? If so there's no wiring present at the existing thermostat to provide any hot water control. Your existing BG product is a single channel device for heating control only.

 

[EFLImpudence]

Excuse me butting in, I've been puzzling over this one. Stem is the expert.

Isn't that thing with the knob a wireless programmable thermostat?

 

[Adam_151]

I think the confusion is that hes replacing the programmer next to the thermostat reciever with the hive, and removing the receiver completely, which OP, is absolutly the right way to do it, its just the original post is a bit vague and we have to try and pick out the pieces from the photographs.

Basically the wiring of the Hive is the same as the original programmer backplate, you have correctly got black in #1, and like on the existing you have nothing on #2 (thats normal), #3 is red as before. #4 is the only difference, thats heating on and you had teh black cable to the removed stat receiver, which then returned on the white, which was crimped to the white of the cable to the wiring centre in the back. So because the Hive is of course stat as well as programmer, you just put the white directly to 4

 

[stem]

Ah OK, thanks @Adam_151 That makes sense. So, if the below is a original programmer. ie provides heating and hot water time control (not a thermostat)

The Hive dual channel fits straight on to it, as it was, and no wiring mod required.

Then if this is the thermostat

Trace the cable back to its origin. When you find the origin of it, note where the wires that go to thermostat terminal 1 (black with red sleeve) and terminal 3 (White with red sleeve) Now disconnect the cable that goes to the thermostat and remove all of its wires. Finally link together the terminals where you have just removed the black and red wires from so that they are now electrically connected.

 

[unknovvn]

@Adam_151
You are right, reading my initial post is a bit vague. I completely removed the programmer and receiver. These only got replaced with the receiver, while the hub is connected to wifi.

@EFLImpudence
The “knob” thing is the programmer, while the other “knob” thing is the thermostat, which i didn’t take a picture off since there’s no wires going to that.

And here’s it is installed



It all worked and turned on with boost and then schedule. My only worry is now, though the CH shows to be on, the boiler is not turned on. And radiators cold. I think this is not related to this, as I did have this issue in the past with the old system

 

[stem]

My only worry is now, though the CH shows to be on, the boiler is not turned on. And radiators cold.

If you have simply disconnected the old thermostat and not made the 'link' I referred to in my post above yours, then the heating wiring will be 'open circuit' and the heating won't operate. The 'link' is required to complete the circuit.