Changing Honeywell room stat (DT90E)

[ddplumbing]

Quick question guys.

I dont deal with heating but this is for my own house so...

I currently have a honeywell T6360 with 4 wires connected:

earth
black to no2
grey to no3
brown to no1



I have picked up a DT90E from my trade shop FOC with no instructions 🙁

It has A, B and C

Can anyone shed some light here for me please.

Boiler is Icos15, controls are Honeywell ST6400C.

Cheers in advance peeps.

 

[dontknowitall]

You could try their website - loads of diagrams there.

 

[ddplumbing]

Cheers, did that... Just don't know which wites which!

 

[dontknowitall]

If you enter DT90E in the search box on their website there are installation instructions.

 

[doitmyself]

T6360 > DT90E

earth > Not used (Make safe, e.g connect to a terminal block)
black to no2 > Not used (Make safe, e.g connect to a terminal block)
grey to no3 > B
brown to no1 > A

 

[ddplumbing]

Many thanks.

 

[twiglet]

Hi DoItMyself,

does your advice also apply to s plan installations? I too am upgrading my thermostat to a newer honeywell dt90e and am struggling to relate the 2 - 1 - 3 labels on the old stat to A - B - C terminal labels on the new one.

I've checked the s plan diagram and all 3 connections from the thermostat do seem to be in use - so I don't want to just disconnect one if it's serving some purpose (tho I am only a keen DIY'er - not an electrical expert).

I can't understand why Honeywell seem to have changed from their original numerical terminal labels when so many of their heating wiring diagrams use this - it's complicated what should be a simple job 🙁

Hopefully warm thanks for a quick reply as it's Cold Up North at the moment 🙂

cheers,

twiglet

 

[Billy Bob Bob]

twiglets you should join the crisps thread lol:tank: