Honeywell ST9100C to Hive

[Sumbu]

Hi,

I am wanting to change our heating controller from a Honeywell ST9100C to a single channel Hive.

I have changed to a Hive at a previous house with no issues so I am confident changing over, however when looking at the wiring on the Honeywell it doesn't seem to match up and therefore I cannot work out the wiring necessary for the Hive.

To give some background to the system, it is an oil fueled combi that works fully, no separate hot water cylinder. There is multi-fuel stove that is connected to the system and can run the central heating separately to the boiler, I have included a picture of the set-up for that. There is no thermostat with the Honeywell controller, one of the reasons we wish to change; I couldn't tell you if there ever was one or if the previous owners spitefully took it with them.

Could anyone please advise how to change the wiring over to a Hive, if this was conventionally wired I don't think I'd have a problem.

Many thanks

 

[RandomGrinch]

It's very straightforward to swap to the single channel Hive - simply replicate what is on the ST9100C backplate on the Hive receiver backplate, except move the black wire (marked with red tape), from terminal 4 to terminal 3 for the Hive.
The earth terminal is also in a different place

 

[stem]

The easiest way is to simply replace the Honeywell ST9100C with the Hive Receiver.

The existing wires move from the ST9100 to the Hive receiver, you can see from the diagrams above that the terminals are like for like, with the single exception of the wire in the ST9100 terminal 4 (heating on), which will go instead to Hive receiver terminal 3 (heating on)

Any existing wired room thermostat needs to be decommissioned to prevent it overriding the Hive. It can't simply be disconnected as this would leave the heating wiring 'open circuit' and it will not operate. The professional way would be to find the origin of the thermostat cable. Note where the wires are connected and disconnect the cable completely. Then link the terminals where the two live switching wires that went to the old thermostat have just been removed from.

Alternatively the old thermostat can be left in place but set to maximum so that it doesn't interfere with the Hive.

 

[Sumbu]

Great thanks guys. Will let you know how I get on.

 

[Sumbu]

All sorted, thank you for your help with this.