Decommissioning wired thermostat for Hive 2 install

[Bhavesh Popat]

Hi All,

I have a Hive thermostat installed at home. This replaced a Honeywell timer and there is also a Honeywell DT-90e wired wall thermostat in place.

I have been unsure of how to completely decommission the wall thermostat. See picture of the initial wiring. Currently have put the live and live switch (wire A (brown) and wire B (grey with brown sleeve) together with a block and left it behind the non functioning thermostat, and the system is working as it should be - but not sure how safe this is?

I have attached the picture of the wiring centre and wondered if anyone would be able to suggest how to disconnect the old wall stat from here - the system has seperate hot water/heating valves, with a kingspan hot water cyclinder and the house has a district heating unit which supplies this. I think it was wired as a Y-plan. sorry I don’t currently have pictures of the current Hive receiver set up - but will add this in when I get a chance.

Thanks in advance

Bhavesh

 

[stem]

Your system appears to be an S-Plan with two, 2-Port motorised valves, and not a Y-Plan which has one 3-Port valve.

To remove the old thermostat, trace the wires from termials A & B back to their origin. [They do usually go to the wiring centre, and one of them will be connected to the live wire of the heating motorised valve] Once you have positively identified the two wires, preferably using a multimeter, note the terminals that they are connected to, and then disconnect them, making sure not to disturb any other wires in the same terminals. Then insert a wire to link together the two terminals together where you have just removed the wires from.

Unfortunately when it comes to wiring centres they don't all follow the same convention, much is down to the personal preferences of the original installer who will have chosen what colour wires to use and which terminals to use for which function. So it's a case of having to know what's connected to the other end of each wire to determine its function.

 

[Bhavesh Popat]

Hi,

Thank you for the advice, I located the two wires in 9 and 10 with a multimeter to check the circuit (both were the same colours as to the thermsostat). I’ve put a small wire to bridge these. System is all working - does this look ok?

Thanks

Bhavesh

 

[stem]

Sorry I can't comment too much unless I knew what is on the other end of all of the wires. There is no standard wire colour scheme and the method of installing them would be at the preference of the original installer.

However if you have traced the live thermostat wires correctly, removed them and bridged the connections that you removed them from it will be OK. And as it's working it would appear to be the case. Ideally as it is a live connection, a brown wire between terminals 9 & 10 would have been more appropriate than a green / yellow wire.

I assume that the wires in the white tape are just the wires that go to the old thermostat that is no longer used. If so, they can be taken out completely, they don't have a function anymore.