Room thermostat swap

[ModernHouse]

Hi,

A couple of years ago I swapped my old style room thermostat for a new digital one (Honeywell DT90E). It works very well and much more accurate than the old one. I now want to do exactly the same swap out at my mums house. She lives in the same style newish build house as me on the same estate, same builder etc., so I was hoping the wires to her stat would be the same colours as mine so I could just copy what I did at mine a couple of years ago. But they're different. The stat I want to fit at my mums is identical to my new one (Honeywell DT90E).

Here is a pic of the wiring for my DT90E, working fine.

Here is a pic of my mums old Danfoss stat wiring (this is the stat I want to replace), the numbering of the contacts from left to right is 4 5 1 3 2.

So the wires go into holes 4 1 and 2 on my mums old danfoss. Just wondering if anyone can tell me which holes on the Honeywell DT90E (A B or C) these 3 wires need to be connected to when I do the swap at my mums.

Many thanks for any help.

 

[jackthom]

The two red wires will go into A and B on the new Honeywell. One is Live and the other Switched Live but they are effectively interchangeable and either can go to A or B.

The black wire, which is a Neutral and no longer needed, should be carefully covered and placed safely to one side. It corresponds to the blue wire in your installation which should also be safely covered and not connected to C, as I at first thought it was when looking at the photo.

 

[ianmcd]

Do you have a wire going into terminal C on your own thermostat ?

 

[ianmcd]

1&2 on Danfoss
A&B on Honeywell (either way round it doesnt matter )
Black wire in 4 safely isolated

 

[ModernHouse]

Thanks a lot for the responses.
I didn't look very closely and assumed the blue wire on my stat was connected to terminal C but it isn't it's just safely isolated/terminated. Terminal C is empty on my honeywell. I think I remember doing that now..... Didn't realise my memory was so bad!
Thanks again.

 

[ianmcd]

Thanks a lot for the responses.
I didn't look very closely and assumed the blue wire on my stat was connected to terminal C but it isn't it's just safely isolated/terminated. Terminal C is empty on my honeywell. I think I remember doing that now..... Didn't realise my memory was so bad!
Thanks again.

yes that is how it should be , it just looked as if it was connected

 

[ModernHouse]

Wired up as recommended at my mum's, all tested and working perfectly. I tested the glide angle of the old danfoss as it was launched toward the bin. Fairly poor ratio. Farewell and thankyou old bi-metallic strip technology.
Thanks again for the replies Ian et al.