Replacing Drayton Dial Thermostat

[johnmcgin]

Hi,

I'm considering replacing my son's Drayton T45 dial thermostat with a Honeywell CM907.

The heating system is a rather ancient ELECTRICAIRE WARM AIR. The current thermostat just controls the fan to circulate the air. There is currently no timer.

Looking at the current thermostat the wiring is as follows:

N - blue
L - yellow
3 (CALL) - red
EARTH - green

I was expecting to see L - red and 3 - yellow. Does anybody have an explanation for the swap?

Will a CM907 work on this system?

Thanks in anticipation.
John

 

[denso13]

I was expecting to see L - red and 3 - yellow. Does anybody have an explanation for the swap?

Not really, as long it connected the same at either end it doesn't really matter. The CM907 is only a two wire so don't use the neutral and put it in a piece of terminal block at the stat end.

 

[D_Hailsham]

I'm considering replacing my son's Drayton T45 dial thermostat with a Honeywell CM907.

The heating system is a rather ancient ELECTRICAIRE WARM AIR.

Have you checked the current rating of the thermostats? The CM907 is only designed to carry a 3A load.