Connecting a Wireless Relay to Boiler

[Jetheat]

I wish to install a new wireless thermostat. I can place the thermostat wherever I want but the wireless relay needs to be connected to the boiler.

Currently, I have a wired thermostat which is connected directly to the boiler.

All the wires arrive into a junction box just below the boiler. See the Junction Box image.
I have marked the 2 wires which are coming in from the existing old thermostat.

So now, I need to disconnect this old thermostat and plug in the new wireless relay instead.
Have a look at the Relay Wiring Diagram which I have attached.

Can someone help me as to which wires to remove and how to connect the relay to the junction box (if that is indeed where I need to plug my relay into)?

Appreciate the help,

JH

 

[ericmark]

The two wires you show go to Com and one of the other terminals shown without any wires connected, but then you are need a line and neutral where the brown and blue is shown, and I can't work out from your picture what cables in the wiring centre are line and neutral also needs an earth talking to it even when there is no where for it to connect to.

 

[Jetheat]

The two wires I have shown in the image go from the Junction box to the existing old thermostat.
So if I was to use these two same wires and plug it into the relay, it would just connect to the old thermostat, instead of to the boiler.

So how do I get around this first issue?

JH

 

[ianmcd]

this is twice you have posted this, it is beyond your DIY capabilities , get a Pro in, you have no clue what you are doing

 

[Jetheat]

This is a different post for actually installing it, and I'd like advice from a DIY forum, thanks.

 

[bernardgreen]

So if I was to use these two same wires and plug it into the relay, it would just connect to the old thermostat, instead of to the boiler.

You need 4 wires to the relay, Live, Neutral, Common and Switched Live together with an Earth. so you need to change the cable to a 5 core cable

and I'd like advice from a DIY forum, thanks.

Based on the questions you are asking the best advice is that you employ a competent person to carry out this work.

 

[Jetheat]

There are many wires coming into the junction box.
Is it possible that 5 of those wires can be used to plug into the relay?

JH

 

[denso13]

Is it possible that 5 of those wires can be used to plug into the relay?

Yes, but you'll still need to have five cores available at the relay which you don't have.

 

[Jetheat]

I have a switch on the wall that can switch the boiler off.
Is it possible that this can have the 5 core cable feeding into that?
It's fed from one of the cables from the junction box.

JH

 

[denso13]

No, highly unlikely.

 

[Jetheat]

So to install the relay, what would need to be done?
JH

 

[oldbutnotdead]

OK, last chance.
That wireless receiver/relay cannot be placed where the existing thermostat is (cos not enough cores for the supply and switched circuit).
It can be placed below that 'wiring centre'.
You need to make sure there is a permanent live and neutral in there (there may not be).

 

[Jetheat]

OK, last chance.
That wireless receiver/relay cannot be placed where the existing thermostat is (cos not enough cores for the supply and switched circuit).
It can be placed below that 'wiring centre'.
You need to make sure there is a permanent live and neutral in there (there may not be).

Ok, lets say I locate the necessary wires like live and neutral.
What about the two I pointed out in my image. They connect from the junction box to the old thermostat and would be useless to attach to the relay.

So how and where should I wire it up?

JH

 

[denso13]

What about the two I pointed out in my image.

They would become the switch wires for the relay and connect to two of the empty terminals. Follow the relay wiring diagram to determine which ones.

 

[Jetheat]

They would become the switch wires for the relay and connect to two of the empty terminals. Follow the relay wiring diagram to determine which ones.

But those wires currently run from the old thermostat to the junction box.
How can they have any power if I connect them to the new relay at the junction box.
The relay would simply be connected to the old thermostat without any power.

JH