Replacing a Honeywell t40 thermostat

[kier]

why are you replacing this reliable thermostat with a complicated digistat

 

[des.lavender]

Just a quick confirmation that the Honeywell T40 does/did exist but the sticker inside also says T6360B 102B - this is what the sticker on the back says too.

 

[dss]

sorry to resurrect such an old thread (i stumbled on it whilst trying to find an answer on google).

I've got a Honeywell T6360 Thermostat (it's similar to/the same as the T40) and i'm trying to work out if i can replace it with a Heatmiser PRT.


The T40/T6360 has the following connections inside it:
2 - Blue
3 - Green/Yellow (although i'm not convinced this is earth)
4 - Red


Can anyone confirm whether the Heatmiser will work / that the wire on connection 3 isn't in fact Earth

Thanks in advance.

 

[333rocky333]

The T40/T6360 has the following connections inside it:
2 - Blue
3 - Green/Yellow (although i'm not convinced this is earth)
4 - Red

Sure a wire was not on the terminal "one"

Should be
1 common
2 neutral
3 demand
4 satisfied

 

[dss]

The T40/T6360 has the following connections inside it:
2 - Blue
3 - Green/Yellow (although i'm not convinced this is earth)
4 - Red

Sure a wire was not on the terminal "one"

Should be
1 common
2 neutral
3 demand
4 satisfied

You are quite right - i assumed the first connection was 1, the second 2, etc. (whereas it goes earth, 2, 3, 1, 5, 6).


So it's actually:

2 - Blue
3 - Green/Yellow (although i'm not convinced this is earth)
1 - Red


Thanks again

 

[333rocky333]

With the honeywell
1 and 3 will be the switching pair

Usually 1 is live and 3 switchlive, but sometimes reversed by mistake.
As per the old post neutral 2 may not be needed on your other stat.

If you can post the connections of the new one, maybe someone can advise.
Do not assume the new stat uses the same numbers.

 

[dss]

here's a photo of it:
View media item 19352
The Heatmiser PRT info states that "Firstly, check that you have at least three wires (excluding the earth) behind your existing stat. If you have, the PRT is compatible." I take it i'm alright then?


again - thanks for the help

 

[333rocky333]

Thats the old stat.
We need to know the new one really.

If it is this one.
http://www.heatmiser.co.uk/manual/dt/dt_manual.pdf

Then it looks like you need a L and N to run it.
Fit a wire link from L to A1.
And switchline to A2
you need to confirm the red wire is your live somehow.
The stat MAY be double insulated and not need an earth, but you need to
check the instructions first.

 

[TicklyT]

Under the paint, is that really a green/yellow wire, or a plain yellow wire?

The other colours, Red and Blue, suggest a 3 core & earth cable.
In that case, the yellow could be a live, switched live or a neutral.
it is almost certainly NOT an earth connection.

The earth wire from the cable may be terminated out of sight on the screw terminal in the back box behind the 'stat, athough most would prefer to see it connected to the earth terminal on the 'stat, with a flylead to the backbox.

If you do have a 3C&E, that looks like it is:-
Red - Live
Blue - Neutral
Yellow - Demand

If it really is Twin & Earth cable, it looks like someone has done something very naughty with the earth wire.

 

[dss]

Under the paint, is that really a green/yellow wire, or a plain yellow wire?

The other colours, Red and Blue, suggest a 3 core & earth cable.
In that case, the yellow could be a live, switched live or a neutral.
it is almost certainly NOT an earth connection.

The earth wire from the cable may be terminated out of sight on the screw terminal in the back box behind the 'stat, athough most would prefer to see it connected to the earth terminal on the 'stat, with a flylead to the backbox.

If you do have a 3C&E, that looks like it is:-
Red - Live
Blue - Neutral
Yellow - Demand

If it really is Twin & Earth cable, it looks like someone has done something very naughty with the earth wire.

I've carefully scraped some of the paint off - and you're correct - it's yellow rather than yellow/green.