Hive heating/hot water installation

[Andrew17856]

Hi

I'd be grateful for some help on rewiring my heating/hot water system to accommodate Hive please. It's not a straightforward install as the hot water and central heating controls aren't on the same backplate at the moment.

This is the present setup:

• Boiler is a Worcester Bosch 40cdi with separate hot water tank
• there is a single channel programmer for the hot water
• about 1m away from that is a single channel wireless receiver for the main central heating - this connects to a wireless thermostat and programmer in one
  
• there is also another single channel wireless receiver in a completely different bit of the house which controls underfloor heating for the conservatory. (I think this will be a straight swap for a single channel Hive multizone heating receiver, so I'm ok on the wiring for this bit)

In terms of the present wiring, my observations are:

• the hot water programmer has permanent live, permanent neutral, hot water live supply, and switched hot water - when hot water is required, the programmer connects the switched hot water wire to the hot water live supply wire.
• the central heating receiver has permanent live, permanent neutral, central heating live supply, and switched central heating - when the central heating is on and calling for heat, the receiver connects the switched central heating wire to the central heating live supply wire.
• if I fully power off the system (at the main fuse box), there is continuity between the hot water live supply and the central heating live supply - this would suggest they're both connected to each other, at least when the system is powered off.
  
• if I power on the system at the fuse box, but leave the boiler powered off, there is 240v on the permanent live as you'd expect, but both the central heating live supply wire and the hot water live supply wire are at 0V
• if I power on the boiler as well (with boiler not firing and hot water/central heating off) there is 240V on both the central heating live supply and hot water live supply.

The Hive dual channel receiver has permanent live, permanent neutral and then hot water off (NC), heating off (NC), hot water on (NO) and heating on (NO). Therefore, if wired in this way, the Hive receiver would connect the switched heating/hot water wires to permanent live when calling for heat. This is different to my present set up, where there are two separate wires that are joined together by the respective programmers for each of hot water and central heating.

My question is therefore whether I can wire it as follows:

• Hive permanent neutral to existing neutral
• Hive permanent live to existing hot water live supply (which appears to be connected to the boiler - not to permanent live, and also to the existing central heating live supply)
• Hive hot water to the existing switched hot water wire
• Hive central heating on to the existing switch central heating wire

Thanks.

 

[Andrew17856]

Having looked a bit more at this, I think the question can be simplified:
The boiler has a live supply (LS) which is downstream of the main power switch on the boiler. At the moment LS supplies the hot water/central heating controllers which switches it through to the live return (LR) to fire the boiler.
Should I connect LS to the permanent live on the Hive dual channel controller or should I connect the Hive to a genuine permanent live?
If I connect the Hive to LS and the boiler was powered off, the Hive controller will also power off. If I connect the Hive to permanent live though it wouldn't, and also you could have 240v on the live return even if the boiler was off.