Hive - Removing Old Room Stat Wiring

[jamiedgwilson]

I'm installing a Hive 2 controller and would like some advice please on removing my old room thermostat. It is currently in my upstairs hallway and I'm replacing it with a Hive multi-zone stat. The current stat has 3 wires as per the attached diagram. I was planning on bridging out 1 and 4 but not sure about 3. It is currently connected to a 2-way valve (diagram also attached).

Can I simply remove wire 3 and connect the brown from my 2-way valve to connection 3 (NO, Heating on) of the Hive backplate?

 

[stem]

I'm replacing it with a Hive multi-zone stat.

The Hive backplate in your picture is only a single channel , so I assume that there is another hive receiver somewhere that controls the other zone.

The room thermostat wires you are interested in are those going to terminal (1) 'Live' and terminal (3) 'Switched Live' They are the two live switching wires that should be joined together.

The other wire going to terminal (4) is a 'neutral' this is there to operate the small heating element in the existing thermostat. it's there to improve the accuracy of the old technology of the mechanical thermostat. It is no longer required and should be disconnected or isolated safely.

I was planning on bridging out 1 and 4

DON'T DO THIS. TERMINAL 4 IS A NEUTRAL. DO NOT CONNECT IT TO EITHER OF THE OTHER TWO LIVE WIRES!

What you ultimately want to finally achieve, and as you have correctly figured, is to have terminal (3) of the Hive receiver 'Heating On' connected to the brown wire of the motorised valve, if you do it directly, or via by using the existing thermostat wires is fine. If it were me though, I would wire them directly together and get rid of the old thermostat wiring completely.

You will need to add a wire to link the Hive (L) terminal to terminal (1) 'common'

 

[jamiedgwilson]

Thanks for the reply.

I have another 2 channel receiver that I am using for downstairs heating and hot water and this one is just for my upstairs heating. I'm fortunate enough that the wiring junction is in a cupboard directly behind the upstairs thermostat so easy to take the wires back to this.

Terminal 3 of the old thermostat is currently joined to the Brown wire of my 2-way valve. Wires from terminals 1 and 4 go into the connector block and are connected to various wires which I'm not sure are.

Just to check I understand:

• I will remove the wire from terminal 4 of the thermostat completely.
• I will also remove the wires from 1 and 3
• I will put a bridging wire in the connector block between the brown wire from the 2-way valve (where terminal 3 used to be connected to) and where wire 1 from the old thermostat used to be.

Why do I need to also bridge between Hive (L) terminal to terminal (1) 'common' on the Hive backplate?

Thanks very much for your help.

 

[stem]

Thanks for the clarification about the other Hive, I just wanted to make sure it was a single channel Hive we are dealing with and not a dual channel as the terminals are different.

I will remove the wire from terminal 4 of the thermostat completely.

Yes.

I will put a bridging wire in the connector block between the brown wire from the 2-way valve (where terminal 3 used to be connected to) and where wire 1 from the old thermostat used to be.

Yes.

Why do I need to also bridge between Hive (L) terminal to terminal (1) 'common' on the Hive backplate?

The 'common' and 'heating on' terminals are basically a switch. When the heating is required, they are joined together. When the heating is not required, they are separated. So you need to connect a live to the 'com' terminal, so that when the heating is required, the contact is made, the 'heating on' terminal is connected to the live, and by its connection to it, so is the live wire to your motorised valve.

The reason for this arrangement is because the single channel Hive is used with combi boilers that are wired directly to the Hive (no motorised valve) Some have 24v circuits for control, so they need voltage free contacts that are not connected to the mains. You need 230V to operate your motorised valve and so it needs to be connected to a 230V live.

This is one difference to the dual channel Hive, the dual channel Hive is not used with combi boilers and so the 230V link is made internally. Therefore it doesn't have a 'com' terminal.

 

[mattclarke68]

Hi Stem, Jumping in on an old thread here. I want to install a HIVE Active heating & Hot water thermostat. My heating system is Boiler Ideal he15
Sunvic 207xl program timer and a Range Tribune tank upstairs and a sunvic TLX9201 Dial on the hall wall. Here is my problem I know from reading and watchin various videos and threads that i have to "link out" the wired thermostat at source but where will i find the "wiring centre" to be able to do this ?
Regards
Matt

 

[stem]

Good question! Unfortunately there is no simple answer. It comes down to where the original installer thought would be the easiest place to put it, which depends on the layout of your property, the location of various heating components in relation to each other, and the installers personal preferences.

Having said that; the most common location is in the airing cupboard near the hot water cylinder as usually the pump, motorised valve(s) and cylinder thermostat are all close by. So that is where I would start looking.

As a temporary measure turning the old thermostat up to its maximum setting so that it never goes off, will stop it interfering with the Hive, but ideally it should be removed and as you say 'linked out'.