Connecting a Wireless Relay to Boiler

[bernardgreen]

Is this a wind up or a wire up. ?

 

[denso13]

How can they have any power if I connect them to the new relay at the junction box.

Because you also need a live and neutral and you only asked about the switch wires as below. Remember the five core cable that has been mentioned on numerous occasions?

Ok, lets say I locate the necessary wires like live and neutral.
What about the two I pointed out in my image.

Remember, electricity is dangerous and can kill.

 

[Jetheat]

In my image, I have identified the two wires going from the junction box to the existing old thermo.

I just need clarification on this point:
Are those wires any use to me, since they connect from the box to the thermo.
If I hook them into the relay, the relay would be connected to the thermo instead of to the junction box.

Can you clarify that part?

JH

 

[bernardgreen]

I have identified the two wires going from the junction box to the existing old thermo.

I just need clarification on this point:
Are those wires any use to me, since they connect from the box to the thermo.

Those wires essential They are part of the circuit from the mechanically operated switch in the thermostat to the boiler to tell the boiler to power up when the switch is closed. ( thermostat~~junction box~~boiler ) You have to replace the mechanical switch in the old thermostat with the electrically operated switch ( relay ) in the receiver.

The receiver requires main power to operate.

 

[denso13]

Are those wires any use to me, since they connect from the box to the thermo.

Yes

If I hook them into the relay, the relay would be connected to the thermo instead of to the junction box.

No, it would be connected to the junction box with the existing cables and wirelessly to the stat.

 

[fixitflav]

In my image, I have identified the two wires going from the junction box to the existing old thermo.

I just need clarification on this point:
Are those wires any use to me, since they connect from the box to the thermo.
If I hook them into the relay, the relay would be connected to the thermo instead of to the junction box.

Can you clarify that part?

JH

Something else to consider - presumably the system is timer controlled, so the existing roomstat only gets power when the timer calls. I assume you could use the timer output to supply the "permanent" live of the relay. The relay outputs, switched live and neutral, going to the points you highlighted on the terminal strip.
How easy that is depends on the timer location. Also I'd check with the relay supplier that it's OK, but I can't think of another way of doing it. You wouldn't want to have timer contacts between the relay output and the boiler.

 

[oldbutnotdead]

Those 2 wires you marked might be volt free, might be 24v or 240v or anything in between. They form a control pair. Your existing room thermostat is a temperature controlled switch (usually a bimetal element in there). When room temp is below the set temperature, those 2 wires are linked (closed circuit). When room temp is above set temp, those 2 wires are not linked (open circuit).
Your tarty wireless receiver replicates this switching function but needs mains power as well (thats why you need extra cores).

 

[Jetheat]

You have to replace the mechanical switch in the old thermostat with the electrically operated switch ( relay ) in the receiver.

The receiver requires main power to operate.

I cant just replace the old thermostat with the new relay because someone here pointed out that the relay takes 5 wires and the old thermostat will probably have 2 wires only.
Otherwise, I could have just taken the old thermostat off the wall and used the same wiring to connect the relay there. But apparently, that wont work.

Have a look at my drawing. I can't understand how connecting the relay to the old thermostat (which needs to be removed anyway, and replaced with a wireless one) will form any type of connection to the junction box.
It would be an isolated connection with nothing to do with the junction box or boiler.

Am I missing something crucial?

JH

 

[ianmcd]

I cant just replace the old thermostat with the new relay because someone here pointed out that the relay takes 5 wires and the old thermostat will probably have 2 wires only.
Otherwise, I could have just taken the old thermostat off the wall and used the same wiring to connect the relay there. But apparently, that wont work.

Have a look at my drawing. I can't understand how connecting the relay to the old thermostat (which needs to be removed anyway, and replaced with a wireless one) will form any type of connection to the junction box.
It would be an isolated connection with nothing to do with the junction box or boiler.

Am I missing something crucial?

JH

That couldnt be more wrong, the two wires connect to the relay from the wiring centre, the thermostat connects to the relay usind a wireless signal no wires between the new thermostat and the relay

 

[Jetheat]

That couldnt be more wrong, the two wires connect to the relay from the wiring centre,

I followed those two wires in the image and they go directly to the existing old thermostat on the wall.
If I disconnect them from the Junction box, then its simply a wire to the old thermostat with no power from anywhere.

 

[denso13]

If I disconnect them from the Junction box

When has anyone told you to do that!! Leave them connected at the junction box and connect the other end to the relay along with a live and neutral and earth!!

 

[Jetheat]

When has anyone told you to do that!! Leave them connected at the junction box and connect the other end to the relay along with a live and neutral and earth!!

Ah, that makes more sense.

So the next step in the puzzle would be to locate the Live and Neutral.
Are there any suggestions as to the steps I can take to locate them?
I have a Multimeter.

JH

 

[oldbutnotdead]

Yes you are missing something crucial- basic comprehension of electrical circuits (as well as the inability to understand simple instructions).
Your best plan now is to leave your house wiring alone, get one of these kits https://www.ebay.co.uk/itm/Electric...-7194-411b-98dd-9e00ede3a70e&epid=20012415422 and learn how electricity works

 

[denso13]

I have a Multimeter.

Use your multimeter to locate a live and neutral in the junction box or follow the cable from the fused spur you posted a picture of earlier.

 

[Jetheat]

Out of all the wires going into and out of the junction box, will there only be one live wire?

JH