Room stat hasn't been wired in, why?

[x60rsa]

Hello

I have noticed at my other halfs rented house that the room stat for the boiler hasn't been wired in. The boiler was replaced a few years ago, its a Biasi combi.

I think i have found the stat cable in the wall near the boiler but even if someone came to wire it in its too short by about two foot.

Can the cable be extended safely as it would be near on impossible to add a new wire without major surgery.

Also why would the boiler have been fitted without the room stat!?

Any help associated thanks. Dave

 

[dcawkwell]

Yes you can extend the existing cable easily to reach the boiler.

Talk about skimping installers.

 

[x60rsa]

Thanks for the reply. Can you buy safe connectors for extending the cable?

Thought about wiring it in myself but would be worried i would wire it in wrong.

There are many wires on the room stat but less connections on the boiler for it which beat me!

 

[dcawkwell]

Thanks for the reply. Can you buy safe connectors for extending the cable?

Thought about wiring it in myself but would be worried i would wire it in wrong.

There are many wires on the room stat but less connections on the boiler for it which beat me!

The old thermostat was probably wired for 240v.
Look at the thermostat only two of the connectors will act as a switch.
Wire those two. Disconnect the other wires. At the boiler there will be
two connectors jumped across with a permanent connector (wire) remove
wire and connect wires from thermostat. To connect wires any mains wire cable connector will be fine.

 

[x60rsa]

Thanks will note all this down. Yes found the loop on the boiler connector.

Just looked at the honeywell wall stat and its wired in as follows, please tell me which i need to keep, remove or change, thanks.

1 = red
4= blue
3= yellow
arrow icon on the stat has wire to it, assuming this is earth

Basically 4wires in total currently connected to room stat.

thanks

 

[dcawkwell]

Pins 1 and 3 I would expect.

 

[x60rsa]

So i am more than likely to keep pins 1 and 3 connected as they are?

 

[dcawkwell]

So i am more than likely to keep pins 1 and 3 connected as they are?

Yes. If you have a multimeter and measure the resistance across 1 and 3 you can verify that the thermostat switches. 1 and 3 will be zero resistant when calling for heat (set 30 degrees setting) and open circuit when not (set 5 degrees). The other pins on the thermostat are not used.

 

[x60rsa]

Yes will try that. Are these stats meant to work correctly on 3 wires?

Would i be better buying a stat suited to a two wire set up?

 

[matt1e]

Depends, what is the make and model of your boiler?

Matt

 

[namsag]

The neutral is required on the stat for the heat antisapator (spelling) to work but it dont affect them that much if its not connected

 

[x60rsa]

It is biasi boiler, 24sm/b, the stat on the wall at present is a honeywell

 

[x60rsa]

I have left the red on the stat connected to point one and the yellow to point 3.

Which goes to which at the boiler end please, thanks.

 

[xr4x4]

it doesnt matter, its just a bridge connection.

open curcuit for off, closed curcuit for on.

the stat just takes the place of this.

simples.