honeywell room stat upgrade help

[jpuk]

i would like some help with upgrading my old honeywell t40 room stat to the digital dt90e as there are 4 wires on the old stat and only 3 on the new one any help would be great,John

 

[Chunky19]

As the new stat is battery operated you don’t need the blue neutral wire so put it in a separate connector out the way. Same for the green earth. Then connect the red live to the A terminal and yellow switch wire to B. Job done.

 

[ericmark]

The bare copper earth with the green/yellow sleeve is not used with new thermostat, I would fold it over and tape it up.

Same with neutral, I fold them over so there is no sharp end likely to stick out of the insulation tape.

 

[jpuk]

thanks was a simple job with the info from you,John