Step 1 - Install the Receivers
The H37XL connections can be identified from the drawing below. I can't see your photo 100% clearly, but it looks to me as if there the following connections are present.
- N,L & E
- Brown wire to terminal (1) 'Zone 1 heating on'
- Black wire to terminal (3) 'Zone 2 heating on'
- Grey wire to terminal (5) 'Hot Water on'
Normally 'Zone 1' and the 'hot water' are connected to a dual channel Hive receiver. From the diagram above you can identify what the wires in each terminal do now, and then it's a matter of moving them to the corresponding terminal that has the same function at the Hive, as per the diagram below. [Do not connect the wire for 'Zone 2' to the dual channel Hive receiver.]
The wire that is connected to the H37XL 'Zone 2' terminal (3) connect to the 'heating on ' terminal of a single channel version of the Hive as per the diagram below
You will also have to run an N & L to the single channel receiver, and insert a link between terminals L and 1 (Com)
Step 2 - Decommission the existing thermostats
The procedure below relates to one thermostat only. You will have to repeat this process for the second zone thermostat also.
Because the Hive carries out the functions of the room thermostat, the old wired 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 thermostat can be decommissioned in three ways, in order of preference (or professionalism) they are.
1. Find the origin of the thermostat cable and disconnect it. Then link the terminals where the two switching wires were connected to together
2. Remove the existing thermostat and replace it with a junction box, connect the two switching wires together and isolate the neutral (if there is one)
3. Leave the existing room thermostat in place and set it to the highest setting. (Or put both of the switching wires in 'L' terminal)