Thermostat question

[mickcooper]

Hi
I have a Baxi Bahama combi boiler that is wired to a frame for a wireless receiver for CH that has been removed an binned along with the thermostat, as picture shows. N blue, L brown, 2 Black (what is this?) and assuming 3 switch. Can anyone advise on what type of wireless thermostat/receiver I can replace it with? I'm a little confused by the 3 wire/4 wire/volt free descriptions on a lot of them. Any help would be great as I'm loath to pay someone to wire this up for me.

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• mickcooper
• 28 Sep 2010
• 1

 

[Taylortwocities]

It looks (horribly) to me that some cowboy has used the earth conductor as one of the signalling conductors.
If so this is very, very wrong and it needs sorting out before your wireless stat is installed.

Needs a picture of how many cables are providing those wires (cannot see from the picture) and also what is on the other end.

Basically you need someone on site who knows heating controls.

 

[mickcooper]

Wow thanks for quick response although not quite what I wanted to hear. Its a single 4 core cable.

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• mickcooper
• 29 Sep 2010
• 1

Here's t'other end. Top is same, bottom is from boiler.

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• mickcooper
• 29 Sep 2010
• 1

 

[ban-all-sheds]

Its a single 4 core cable.

No it's not - that's just how the cretin who installed it used it.

It's a 3-core and earth cable.

 

[jj4091]

There are different ways to connect different stats for different applications. You will get a wiring diagram with the new stat. This should give you an option to use your exsisting cable without any problem. You may have to sleeve the earth core properly.

 

[Taylortwocities]

Just to reinforce the above.

If you use the existing cable, the earth conductor must be connected only to earth. That gives you 3 cores to connect your wireless stat. That may be enough for your system depending on your heating plan and the stat type.

If you mount the wireless receiver will be close to the wiring connection centre there will be nothing to stop you running in an additional cable, if needed.

EDIT: I just had a look at your picture of the wiring centre. The earth wire has been used to carry the permanent live to the stat location.
This is not necessary as it can be looped in the stat backplate. That will leave the green/yellow to do the job it is intended for (EARTH).

If you get the wireless stat we can tell you how to connect from your pics.

Meerkat

• Taylortwocities
• 11 Dec 2009
• 53

Simples!

 

[londonboy]

You can use that 4 core cable with any wireless thermostat.

At the boiler end remove the green/yellow and put it with the other green/yellow (presumably from a spur or plugtop).

Remove the green/yellow at the backplate, remove the sleeving, and terminate it in a small connector block.

If you buy a Drayton or Danfoss wireless stat then you could simply click it onto that existing backplate you have there.

We cant say what to do with the remaining wires until you have decided which thermostat you want.

 

[londonboy]

.... That may be enough for your system depending on your heating plan and the stat type.

....

Its a combi, it only needs a 230v switchline!

 

[mickcooper]

Thanks all for help, much appreciated. I see now the earth isn't actually an earth, so will this baby do the trick ?
http://cgi.ebay.co.uk/Salus-Digital...ooling_Air&hash=item1e599d98b4#ht_3919wt_1137

 

[Taylortwocities]

Don't know anything about Salus, but should be OK for your use.

It says "Industry Standard Backplate". You may be even able to use the existing plate - having first made the wiring changes outlined above.

 

[londonboy]

Bear in mind someone has posted in the plumbing forum saying the Salus are difficult to use.

I recommend honeywell, although it doesn't have the backplate, I can still tell you where the wires go.

 

[mickcooper]

So I bought the Salus and this is the wiring diagram and connection plate on back of receiver, it's not same as current one so I can't plug in as-is which isn't a problem. Be great if someone could advice on wiring needed for this from boiler as in earlier photos.

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• mickcooper
• 4 Oct 2010
• 1

[/img]

 

[londonboy]

So I bought the Salus and this is the wiring diagram and connection plate on back of receiver, it's not same as current one so I can't plug in as-is which isn't a problem. Be great if someone could advice on wiring needed for this from boiler as in earlier photos.

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• mickcooper
• 4 Oct 2010
• 1

[/img]

Brown - L
Link wire between L and COM

Blue N

Black - NO/on terminal.

Do as I said above with the earth wire (altering it in the boiler etc), terminate it in a connector block behind the Salus receiver.

 

[mickcooper]

Cheers londonboy and thanks for taking time to sort this. Worked a treat, just in time before the snow comes!