Hive install on combi with no existing thermostat

[TCTav]

Hi All,

I've just purchased a single channel hive to control our combi boiler as the built in timer has broken. It is a Sime Ecomfort Plus 25 HE - EV, we have no existing thermostat. (Manual can be found at https://www.freeboilermanuals.com/asset ... V-Inst.pdf, diagram page 20 )

So for the Hive I need the following:

Hive.PNG (46.46 KiB) Viewed 5457 times

My boiler has the following PCB wiring:

boiler.PNG (139.58 KiB) Viewed 5457 times

From my understanding I know I need to get a live and neutral feed from either the boiler or the fuse spur feeding the boiler, to the ports on the receiver.

I am unsure then whether I require a common (seems that people do a bridge from Permanent live to Common port on the receiver).

I think I then don't require a heating off connection, so can ignore this port on the receiver.

Finally I think I need to remove the link between connections 5 and 6 on the boiler as if I were wiring in a room thermostat, and need to connect the switched live to the heating on (NO) port on the receiver, how do I identify if its 5 or 6?

So my assumptions for the connecting up are as follows:

Hive - Boiler
N = N
L = L
C = Bridge from L on Hive
Heat off = N/A
Heat on (NO) = Terminal 5?

Does this sound right, and if not could you point out any errors before I connect.

Thank you all,

Tom.

[ericmark]

It does seem 5, 6, 7, and 8 are simple switches on/off but it does not show voltage so could be 24 volt not 230 volt so I would wire as volt free and not use any links.

As far as I can see it is not designed for a switched thermostat only a switched frost stat, is seems as if designed for a special thermostat likely opentherm or something like that?

Pre condensate boilers used simple switches, then early condensate boilers used return water temperature, latter ones used things like Bosch Worcester SX and Nest OpenTherm where the thermostat does not switch boiler on/off but turns it up and down and alters flame height.

It would seem from the circuit diagram you need a thermostat matched to boiler which turns flame height up or down not a simple on/off like done with Hive?

[TCTav]

Thanks for the suggestions Ericmark, but turns out friend of a friend was a British gas fitter who pointed me in the right direction. I kind of understand it, it's effectively always on with the hive acting as a switch in the circuit to open or close activating boiler.

Solution:

Leave link between 5-6, remove link between 6-7, then wire as follows

Hive - Boiler
Live. - Live
Neutral - Neutral
Common - 7
2 - N/A
3 - 6
4 - N/A

Old timer switch is left in on position, and I guess at some point I can bypass it but I'm not too fussed.

Hope that helps any in my situation, but obviously is specific to this boiler only!

Tom

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