Author Topic: CH Room thermostat wiring question  (Read 389 times)

CH Room thermostat wiring question
« on: November 22, 2017, 12:16:39 pm »
After some deliberation with SWMBO I agreed to replace the bog standard Drayton RTS1 analogue room stat with a digital one. I chose a Honeywell DT90E. So I removed the faceplate on the Drayton stat, and found it's a 3 wire (plus earth) installation - Live, Neutral and Call. Looking at the Drayton wiring diagram it's a switched live between Live and Call. Makes sense.

The wiring diagram for the Honeywell shows only one 3 wire installation, the rest being 2 wire.  If I follow the 3-wire diagram will it work which wires should I connect where? The Live is obviously connected to terminal A.  Do I need to connect the Neutral at all, and if so will it be to C?, or do I tape it up and just connect the Call to terminal B?

http://www.draytoncontrols.co.uk/sites/default/files/U%26IG.%20RTS2.pdf

file:///Users/richardfletcher/Downloads/DT90E-Spec-Sheet%20(1).pdf

TIA
We are making a New World (Paul Nash, 1918)

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: CH Room thermostat wiring question
« Reply #1 on: November 22, 2017, 12:28:04 pm »
Looking at the diagrams on the web relating to DT90 (your link is to a file on your PC) it is switched live.  So connect live to terminal A and call to terminal B. Option A from teh diagram



DO NOT CONNECT NEUTRAL TO TERMINAL C

If you connect Neutral to terminal C you will short live and neutral together when the heating is not being called.  This would potentially destroy your new thermostat as a minimum or cause a fire in your house worse case.

In teh nicest possible way may I suggest you might be best asking an expert to look at fitting this for you.  :thumbsup:
Regards,

Jason

Re: CH Room thermostat wiring question
« Reply #2 on: November 22, 2017, 01:16:29 pm »
LOL thanks - I realised the potential short issue whilst eating lunch :-) - penalty of rushing my post in order to get the lunch ready for my better half! So I'll just tape the neutral out of the way in the wall box.
We are making a New World (Paul Nash, 1918)

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: CH Room thermostat wiring question
« Reply #3 on: November 22, 2017, 02:27:00 pm »
LOL thanks - I realised the potential short issue whilst eating lunch :-) - penalty of rushing my post in order to get the lunch ready for my better half! So I'll just tape the neutral out of the way in the wall box.

 :thumbsup: Yes that should be fine, just make sure its a good covering and any potential causes that might cause a short are mitigated against :)
Regards,

Jason