Thinking of Wireless Room Thermostat

[kevin12345]

Hello,
I'm thinking of replacing my wired Room Thermostat with a wireless one that I can move from room to room.
The set up is I have a conventional gas boiler in the Kitchen and a wired room thermostat in the Hall downstairs and a central wiring box upstairs in the Airing cupboard.
I have attached a photo of the Wiring Box. Looking at the Photo from left to right the first white cable goes to the central heating pump, the middle white cable goes to the Hot water cylinder thermostat and the right hand Black cable goes to the 3 port divert valve.
I wish to replace the wired hall thermostat with a simple temperature only wireless thermostat that I can move from room to room. It does not have to be Programmable because the boiler has a programing unit situated beneath it.
My question is does the Wired Hall Thermostat go back to the wiring box in the Airing cupboard, if so how do I know which wires they are?
Is the wiring box the correct place for me to connect the new wireless thermostat, if so can anybody tell from the Photo where I should connect it?
Many thanks for reading. View media item 59365

 

[Dan Robinson]

The Honeywell DT92E has all the instructions you need.

But why not get a programmable room thermostat and benefit from TPi optimisation?

 

[kevin12345]

Thanks for your reply.
I'm just trying to make the Job as simple for me as possible, as I already have a programmer that operates the times for the heating and hot water I just wanted to replace the thermostat with a simple one.
I have been looking at a Celect Simple Wireless RF Room Thermostat Volt Free.
Can any body tell anything about my wiring from the Photo? I just don't want to buy anything yet if it turns out to be more complex then I think and I get stuck

 

[D_Hailsham]

You say you have a diverter valve, which is unusual. Do you mean a mid-position? The valve's make and model number would help clear this up.

 

[kevin12345]

Hi,
It is a 3 Port valve - Danfoss HSA3

 

[twgas]

I would suspect it would be best having the receiver next to the programmer as there does not appear to be a permanent live in your wiring centre.

 

[D_Hailsham]

It is a 3 Port valve - Danfoss HSA3

That's a mid-position valve, so the CH control wire is the brown one within the black cable. It connects to terminal 5 (bottom).

Terminal 5 (top) is the switched live from the existing thermostat. This is where terminal B for the new stat will connect.

I can't make out the cable to the existing stat (ie the one with a wire to T5). Can you tell me which wire goes to which terminal?

 

[kevin12345]

It is a 3 Port valve - Danfoss HSA3

That's a mid-position valve, so the CH control wire is the brown one within the black cable. It connects to terminal 5 (bottom).

Terminal 5 (top) is the switched live from the existing thermostat. This is where terminal B for the new stat will connect.

I can't make out the cable to the existing stat (ie the one with a wire to T5). Can you tell me which wire goes to which terminal?

Hi Hailsham,
Thanks for reply.
The other wires from the cable that you say is the existing stat go as follows,
The Blue goes to Terminal 2 and the red terminal 4.
Hope that helps

 

[D_Hailsham]

The other wires from the cable that you say is the existing stat go as follows:
The Blue goes to Terminal 2 and the red terminal 4.

That's useful.

The A terminal of the wireless relay will connect to terminal 4 and the B to terminal 5. But don't do anything yet!

However there is still the problem of getting a permanent supply (i.e. is not switched on/off by the programmer) to the L and N terminals. As twgas says the wiring block does to appear to have one. Do you have a multimeter (and know how to use it )? If so check for 240Vac between terminal 2 (neutral) and all other terminals with CH and HW turned off at the programmer. If there is more than one, check which drops to 0Vac when you turn HW ON at the programmer. The other one may be a permanent live. Check by turning power on and off to the system.

If you can't find a permanent live you will have to mount the relay near the programmer, which will require a 2-wire cable from relay to programmer and a second 2-wire cable from relay to the junction box.

Come back when you have checked out the permanent live.

 

[kevin12345]

Thanks for your instructions, very clear.
I have a feeling there is not a permanent live.
Here are the results
Terminal 7 is 240v live when both water and heating is OFF but drops to Zero when HW is switched on.
Terminal 9 is Zero when both HW and Heating is OFF but is 240v live when either Heating or HW is switched on
When Power to the System is switched OFF they are all Zero

I have attached a photo of the Programer and cut off switch to the system.
You have given my very good advice so far, thank you.

Any Ideas what my next step is now?

Thanks View media item 59534 View media item 59365

 

[D_Hailsham]

I have a feeling there is not a permanent live.

Your feeling is correct.

I have attached a photo of the Programmer and cut off switch to the system. Any Ideas what my next step is now?

The problem now is to get a permanent live, which is controlled by the same
cut off switch, and ideally near the junction box.

Where is the junction box located - is it anywhere near the programmer?

 

[kevin12345]

I have no idea where the Junction box is.
The Photo shows the Programmer which is under the boiler and the switch below it turns the power on/off to the System.
What should the Junction box look like?
There is nothing on the wall around the Boiler and nothing in the upstairs airing cupboard apart from the wiring box that I photographed.
Could it be it be in the loft above the airing cupboard?

 

[D_Hailsham]

I have no idea where the Junction box is.
...
There is nothing on the wall around the Boiler and nothing in the upstairs airing cupboard apart from the wiring box that I photographed.

You have been confused by the terminology. The 'junction' box is the 'wiring' box!

So the programmer is downstairs and the wiring box upstairs; that could make things difficult. But don't give up as I've seen a possible solution.

Is that a plain cover plate to the right of the cut-off switch? If it is, remove the plate. With any luck, there will be some wires and one will be a permanent live. If you can find out what all the wires do, so much the better.

 

[kevin123456]

Hi,
The Plate to the right of the cut of switch is the over the top worktop fused spur switch for my washing machine plug socket that is under the worktop.
So this switch when on is a permenant live in it.
When you say find out what all the wires are, do you mean in the Junctin/wiring box?
Thanks

 

[kevin123456]

Ask a silly question but why is'nt the permenant live going to the systerm cut off switch any good?
Thanks