naughty British Gas

[bhm1712]

That's my day unexpectedly planned then!

Changing the room stat receiver today and have found that when BG installed it (over 5 years ago now however) they have used a 1.0mm2 three and Earth cable. Problem is, the receiver (old and new) requires 4 core and Earth to be installed correctly and Im fuming that they thought it acceptable to use the CPC of this type of cable as a switched live and even put green and yellow sleeving on it still!

So now i need to work out how I'm going to pull in a 4 core and Earth cable over a distance of about 10 metres without ripping the floorboards up.

Thanks British Gas.

 

[sparkwright]

1.0mm2 core and earth? Flat cable with a bare earth wire?

That is unacceptable.

I wonder if there is an alternative system you could have to save the wiring.

I would say get them back, but you'd probably get a rubbish job.

Send pictures if you like.
We like that sort thing.

 

[bhm1712]

1.0mm2 core and earth? Flat cable with a bare earth wire?

That is unacceptable.

I wonder if there is an alternative system you could have to save the wiring.

I would say get them back, but you'd probably get a rubbish job.

Send pictures if you like.
We like that sort thing.

Yes mate - flat cable core and earth with un-insulated CpC being used as a live ! Totally out of order. Horrifying to think that the cable enters the kitchen cubby hole where the Mrs puts the vacuum and ironing board etc - cable is clipped to door frame and could easily be nicked or similar by her if she's not careful.

I'll get some photos and post them up later.

I'm thinking it may be a much easier and better solution to mount the receiver below the boiler and run a flex to it and to get rid of the long run of core and earth. I've got a couple of meters of 5 core flex knocking about somewhere in the shed. Can't see there being any comms issues between stat and receiver.

 

[Taylortwocities]

It is usual to put the receiver near the wiring centre so that would be a better, and correct cable, option.

It sounds like BG put the receiver just where the old thermostat was (3-core and earth will have been all that needed). It was easier for them to do that than to do the job properly.

Of course, removing the old stat would have left a hole & cable in the wall that would need making good, so maybe the householder at the time said they did not want that.
Anybody's guess I suppose…..

 

[Echo the husky]

It is usual to put the receiver near the wiring centre so that would be a better, and correct cable, option.

Yes, but if it is a Y plan there will not usually be a permanent live at the wiring centre if the mains supply goes to a remote programmer first. It's not great to power the receiver with the heating on signal from the programmer, as some stats can take ages to reconnect the transmitter and receiver after the power is switched off.

 

[bhm1712]

It's an S plan. There's plenty of permanent live terminals to choose from

 

[Echo the husky]

That'll save some effort then!

 

[SimonH2]

Thinking laterally ....
Could you rewire it to use permanent L&N plus switched live, and add a relay at the boiler end ?

 

[bhm1712]

I could have done, but for the sake of a metre of 5 core, 15 minutes of making ends off and connecting it wouldn't have been worth it.

 

[stardanny]

Changing the room stat receiver today and have found that when BG installed it (over 5 years ago now however) they have used a 1.0mm2 three and Earth cable. Problem is, the receiver (old and new) requires 4 core and Earth to be installed correctly

I am confused.

You say BG used 1.0mm2 three and earth cable? That is fine as 3 cord and Earth is suitable for room stat, one for permanent live, one for neutral, one for switch live and Earth wire.

Daniel.

 

[Taylortwocities]

This is the problem with BGs installation.

m fuming that they thought it acceptable to use the CPC of this type of cable as a switched live and even put green and yellow sleeving on it still!

 

[diyer56]

Changing the room stat receiver today and have found that when BG installed it (over 5 years ago now however) they have used a 1.0mm2 three and Earth cable. Problem is, the receiver (old and new) requires 4 core and Earth to be installed correctly

I am confused.

You say BG used 1.0mm2 three and earth cable? That is fine as 3 cord and Earth is suitable for room stat, one for permanent live, one for neutral, one for switch live and Earth wire.

Daniel.

Unless it is a combined receiver for both HW and CH control (for example the Hive wireless receiver)?

It would then need
- permanent live
- neutral
- switched live (hot water)
- switched live (central heating)

 

[SimonH2]

That is fine as 3 cord and Earth is suitable for room stat, one for permanent live, one for neutral, one for switch live and Earth wire.

Or, the control circuit isn't just a switched live. Several scenarios come to mind :

• The control circuit is low voltage.
• The stat needs a permanent supply, but the control circuit needs to be off a switched live from a timer/programmer.
• As mentioned, there's more than one switched circuit

At my parents they had the opposite issue. When BG fitted a new system for them, they initially wired the stats with 4 wires - permanent supply, plus switched supply from the programmer to the contacts, and the switched circuit back to the zone valve. However the stats have a predictive function so the closer the room temperature to setpoint, the longer they delay switch on. So they were "called back" to alter the wiring to a 3 wire setup.

 

[bhm1712]

Changing the room stat receiver today and have found that when BG installed it (over 5 years ago now however) they have used a 1.0mm2 three and Earth cable. Problem is, the receiver (old and new) requires 4 core and Earth to be installed correctly

I am confused.

You say BG used 1.0mm2 three and earth cable? That is fine as 3 cord and Earth is suitable for room stat, one for permanent live, one for neutral, one for switch live and Earth wire.

Daniel.

Why are you confused?

To function correctly the thermostat requires a permanent live and a neutral to power it up. It then also requires a live supply from the programmer when the programmer turns the heating on and a switched live back to the boiler to turn the boiler on when the thermostat calls for heat. It also then needs an earth running to it regardless of whether it is double insulated or not in order to comply with Bs7671.

 

[bhm1712]

So minimum 5 core required.

If you are happy to have constant comms issues between thermostat and receiver then you could possibly be happy with 3 and Earth and have the programmer heating on live powering up the thermostat receiver and linked across to also provide the 230 volt common for the relay. Doing this means each time the heating turns off so does the receiver and so the receiver and thermostat have to restablish comms each time the heating comes on.