From Honeywell To Hive

[Jayymacc]

I'd be grateful for any help with this ...

I'm looking to replace my Honeywell ST9400C CH/HW controller (with existing Honeywell wireless thermostat) with dual channel Hive.

Do I just leave the existing wireless thermostat receiver as it is or do I have to do anything to decommission it?

The wiring inside the Honeywell pretty much corresponds with the Hive, assuming it's OK that the "off" terminals and the earth terminal are all empty.

 

[stem]

Your Honeywell is wired as below....



...so correspond to the Hive dual channel version as below



This means a straight swap of the wires from the Honeywell to the Hive.
L to L,
N to N,
3 to 3,
4 to 4,

As you don't give a make / model for the Honeywell wireless room thermostat, I can't give wiring references. However, it will need to be decommissioned to prevent it will overriding the Hive. [It can't just be disconnected, otherwise the heating wiring will be 'open circuit' and the heating will not operate] This can be done by tracing the wires back from the thermostat receiver and finding where they originate from. Then disconnect them at their origin, and the two terminals where the switching wires came from should be joined together. Any neutral, if present can just be disconnected. If you need any more help with this, please provide details of the existing thermostat.

 

[Jayymacc]

Many thanks for that, it is a Honeywell and I've attached a couple of pics.

Could I just join up some of the wires in the receiver?

 

[stem]

Yes you can. Put the grey and black wires at the Honeywell R6660D in the same terminal, A or B, it doesn't matter which.

 

[Jayymacc]

Thanks for the advice, I'll give it a go. There are only 2 electricians local to me and they both "don't do Hive".

 

[Jayymacc]

But if I want to get rid of the receiver unit completely, what would happen to the blue and brown wires please?

 

[stem]

To do that, you would need to:

1) Disconnect and remove the 4 core cable between the receiver and the wiring centre completely.

2) Then looking at the two terminals in the wiring centre where the grey and black wires originally came from, all of the wires that go into both terminals need connecting together. This can be done by either inserting a link wire between the two terminals where the black and grey were connected, or moving the yellow wire that was connected to the grey wire into the terminal where the black wire came from. [I'm assuming that the yellow and grey wires are the only two in that terminal presently, sometimes it's difficult to tell in a photo]

 

[Jayymacc]

Awesome many thanks. I think that's what I had better do. Currently (and this is after doing nothing at all apart from opening up and then shutting the thermostat receiver box) the heating will only fire up when the hot water tank is asking for more heat. i.e. although the thermostat/receiver appear to be linked up and working fine (lighting up the light on the receiver) it is not firing anything up. Perhaps I broke it.

 

[stem]

That sounds like a fault somewhere. Maybe you have disturbed something. A fault with the existing receiver would prevent the central heating 2-port motorised valve opening so it wouldn't even come on even when the water does.