Replacing old Honeywell room thermostat with new wireless on

[RF Lighting]

Do we know that? I can't find any mention of that in any of the OPs posts.

I find it best to deal with facts rather than assumptions when working with electricity.

 

[doitall]

Help.

Have old Honeywell traditional 3 wire thrmostat on lunge wall. Live + 2 x neutrals

And what would you consider the 3 wires to be for, using electrical skills and engineering judgement, based on your knowledge of how heating systems work, in conjunction with a room stat.

I'll assume you know the boiler has a 240Vac switched live terminal.

 

[RF Lighting]

One red and two blacks would be a very unusual wiring configuration. All I asked for was a photo of the wiring so we could find out for certain what the OP actually has, but apparently we don't need this as you can guess what's already there.

 

[doitall]

You don't need to guess.

The wires are connected to 1-2-3 and most pro sparky or heating guy. will know what they are, irrespective of the colour..

Now if the OP has pulled them out and shuffled them up, it's another story.

 

[RF Lighting]

What if one of them is the earth used as a switched live? Is it still ok?

 

[doitall]

What if one of them is the earth used as a switched live? Is it still ok?

I bet there's 1000s out there that have, and most wired by sparkies as they have red sleeves.

 

[RF Lighting]

Oh so it's ok then because there's loads like it? If it is wired like that, then it certainly wasn't wired by an electrician.

 

[leoleo]

Hi guys sorry to cause a bit of disagreement between you. I have managed to get my device working not blown myself up or the house. Seems to be ok just got to make sure the thermostat is in the right place so it can communicate with the new control unit.

thanks for all your help and advice I could not have done it without you both.

 

[doitall]

So how did you wire it leoleo. ?

Plumbers and sparkies never agree, unless they are working for us.

How many plumbers or DIYers do you know that carries red sleeving in stock, RF

 

[RF Lighting]

Personally none, but none of the earths used as lives that I've seen have ever been sleeved red.

 

[D_Hailsham]

Step 3 - you mention EP2002 position 4 to A (that's fine), but then in Step 4 you go from Boiler ON (which is also 4 on the EP2002) to B. Two connections from EP2002 no.4 - is this correct.

I know you have solved the problem, but the above doesn't make sense.

There are three wires connected to the old stat so they should go to three separate terminals (4, N and another) in the EP2002. What you say above implies that two of them go to the same terminal (4) in the EP2002.

What was the eventual solution?

 

[doitall]

You can't do it at the programmer, unless you interrupt 4 and then leave the old room stat connected.

Be interesting to find out whether any MV's as well.

 

[D_Hailsham]

You can't do it at the programmer, unless you interrupt 4 and then leave the old room stat connected.

Be interesting to find out whether any MV's as well.

The OP is installing a plain vanilla thermostat, NOT a programmable stat.

 

[doitall]

You can't do it at the programmer, unless you interrupt 4 and then leave the old room stat connected.

Be interesting to find out whether any MV's as well.

The OP is installing a plain vanilla thermostat, NOT a programmable stat.

I know the stat Dave.

Have a L&N + a switching pair, with a relay box.

What I'm asking is what did the old stat control.

There's a good chance there's an S or Y plan MVs.

4 in the prog would go to 1 in the stat, and 3 in the stat would then go to the white.

Of course 3 in the room stat may be the switch live to the boiler, either way the existing stat has to stay or be re-wired from the boiler.

 

[leoleo]

Thank you very much everyone.

Didn't expect an online battle over my call for help.


Well, I've followed your advice and it works at treat.

Thank you all for your help.

Regards.