change from manual to digital c/h thermostat

[mickcoulson]

hi... I am wanting to change my SONDER TR01 COD 1001 manual thermostat to a HONEYWELL DT90E + ECO digital but am not sure about the wiring. my old one has three wires red / black / earth . the live is connected to no.1 terminal and the black is connected to no.3 and obviously earth to earth terminal. the honywell has only 2 connectors. what do I do with the earth wire ( put it in a terminal block ? ) and which wire goes where on the digital connections
any help please
mickcoulson

 

[jackthom]

Just take the two main wires to terminals A(red) and B(black) on the new thermostat. The redundant Earth wire must be safely covered and kept away from the other Live wiring.

 

[mickcoulson]

Just take the two main wires to terminals A(red) and B(black) on the new thermostat. The redundant Earth wire must be safely covered and kept away from the other Live wiring.

hi...I have wired the thermostat like you said ( red to a / black to b ) but when I press the on button the screen is blank ...help

 

[jackthom]

Maybe the batteries have been disturbed? I would pull them out for a few seconds then make sure they go back firmly in place.

 

[mickcoulson]

Just take the two main wires to terminals A(red) and B(black) on the new thermostat. The redundant Earth wire must be safely covered and kept away from the other Live wiring.

hi...I have wired the thermostat like you said ( red to a / black to b ) but when I press the on button the screen is blank ...help

sorry I have taken the batteries out and put them back in...it is now working
cheers

 

[mickcoulson]

Just take the two main wires to terminals A(red) and B(black) on the new thermostat. The redundant Earth wire must be safely covered and kept away from the other Live wiring.

hi...I have wired the thermostat like you said ( red to a / black to b ) but when I press the on button the screen is blank ...help

sorry I have taken the batteries out and put them back in...it is now working
cheers

by the way do I need the batteries , are they just for back up ?

 

[jackthom]

Yes definitely you need them, the batteries are the only power supply for this room thermostat.


You can buy units which are mains powered but they need Live and Neutral wires where they are installed.