How to wire a DT90E from a Potterton EP 2000

[cowlerc]

Hi,

I have just moved in to my new home and have found the room thermostat is damaged and not working correctly. The front cover is missing so I'm not sure what model the thermostat actually is.

It is wired:
Terminal 1 : Red (fairly sure this is Live)
Terminal 2 : Blue (fairly sure this is Neutral)
Terminal 3 : Yellow (fairly sure this is Switch Live)

And connected to a Potterton EP2000

I have purchased a Honeywell DT90E as a replacement.


So to my question;
What wires should I connect to its terminals, A, B & C ?

Any help would be great

 

[Whitespirit66]

Without knowing what your original stat is, its difficult for me to confirm what you say re. Live/Neutral/Sw Live. If you have a multimeter, you can easily check these.

On the DT90E -

Live To A
Switched Live To B
Terminal C not required
Neutral wire - not required - tape end off

 

[HERTS P&D]

Red wire - live goes to A
Yellow wire - switch live to B
Blue wire which is neutral needs to be made safe and put into a butt connector as it is not used.

Please check that your wires are correct as mention as above

Andy

You beat me to it WS

 

[Whitespirit66]

No worries, just glad we came to the same conclusion!

 

[cowlerc]

Hi,

I tried and i can here the DT90 switching however the boiler is not responding.
The bad news is that I don't have a multi tester.
From the old back plate (dark brown) I can say for sure that the old one was a Honeywell stat and that it has a part number of 4200 3878 on it.
Looking at it on the underside
Terminal 1 & 3 are connected either side of a light blue capacitor.
Terminal 2 is connected to a resistor prior to joining with terminal 3

Really need some help on this house is freezing.

Thanks in advance