replacing an RS1 thermostat with Honeywell DT90E

[mickcottam]

I am replacing the old RS1 thermostat with an DT90E.

The current wring for the RS 1 is Neutral, Live and call in connection 3. There is also an Earth.

Could someone please advise how these wires translate into the connection for the DT90E which are described as A, B, C.

Also it has a battery compartment. I'm assuming this is a back up for power loss rather than being the only power source. I can get the DT90e working with Battery power but it doesn;t work without the batteries in.

Any help is very much appreciated.

Thanks

 

[denso13]

Live to A, call to B and terminate the neutral safely (not required). The batteries are needed for the unit to work.

 

[gas112]

Live into A ,wire from 3 into B snip the earh and safely isolate the neutral either by the stat or in junction box it comes from.
It needs the batteries to work ie sensing the temp and switching on and off. they are not there for back up

 

[mickcottam]

Thank you both. It's very much appreciated.

 

[Ryansimmo]

Hello,

I have searched the forum and have done this exact same thing as Mick but the heating ios not coming on in the morning.

Is there any suggestions to assist me please.