Hive Dual Channel Controller Wiring Question

[corkyboy]

I am replacing a Honeywell ST9400c Controller with a Hive. The wiring diagram for the Hive shows terminals 1&2 as HW & CH reserved for "Off" . On my existing Honeywell no wires are attached to these terminals, see attached image but there are 2 spare wires taped up but not connected.
If I wire up the Hive as per the Honeywell will the receiver function normally e.g. Alexa "Boost heating" commands etc.
We have an oil fired condensing boiler, with a separate tank for HW storage.
TIA, Colin

 

[stem]

That's fine; it's the type of heating system that you have that determines which terminals have wires in them. So, if you don't have wires in 1 & 2 now you won't need wires in them at the Hive.

From an electrical point of view, the Honeywell and Hive are identical. They both contain two simple on/off switches one for the heating, and one for the hot water.

If there is an existing room thermostat somewhere, that will either need to be set to it maximum setting to prevent it interfering with the operation of the Hive, or removed and a small wiring modification made to complete the circuit. It can't just be disconnected.

If you don't know what is on the other end of the spare wires, in case they are connected to something, they should be isolated safely out of the way. Normally I would put them each in a separate new additional screw terminal. However, if you know that there isn't anything connected to the other end of them, they can be left as they are, and tucked out of the way.

If your system is fully pumped [ie the heating and hot water are both connected to the boiler via the pump] then the Hive will be configured for that, if your system is old and has gravity circulation of the hot water around the hot water cylinder, and only the central heating is pumped then Hive should be set to Gravity Mode.

 

[corkyboy]

Thanks for your reply Stem, much appreciated. The system is fully pumped, motorised valves etc. With regard to the existing thermostat, image attached, if I just disconnect the red wire and blank it off will that disable it safely or do you have a better suggestion?

 

[ericmark]

No that will not work, either it needs linking at thermostat or wiring centre or turn only thermostat to full. I would to start with at least turn only thermostat to full. I think this is wiring for old thermostat

if so then a link between 1 and 3 will prevent it turning off.

 

[stem]

With regard to the existing thermostat, image attached, if I just disconnect the red wire and blank it off will that disable it safely or do you have a better suggestion?

That will leave the heating open circuit and it will not work. As I said before

a small wiring modification made to complete the circuit. It can't just be disconnected.

To do it properly I prefer to remove the thermostat completely, because a) it's a blot on the wall, and b) whilst the thermostat remains connected, its internal 'anticipator heater' will remain connected and working. If you do wish to remove it completely, here's how:

1) Trace the cable from the thermostat back to its origin. When you find the origin, make a note where the red and yellow wires are connected.
2) Now disconnect all of the wires in the cable that go to the room thermostat and remove the cable.
3) Insert a link to join together the terminals where the red and yellow wires have just been removed from, so that they are electrically connected and the circuit is completed.

Alternatively, you could remove the thermostat and put the wires connected to it in a junction box. The Blue neutral wire goes in one terminal, the earth in another terminal so that they are both isolated. Finally the red and yellow wires go in one terminal together.

 

[corkyboy]

Thanks Stem for your input. I've decided to leave it intact, should we move house I will that way keep the opportunity to restore it to the old system and remove the Hive if the potential purchaser prefers..