replacing a faulty room thermostat

[carlymart]

hi i hope someone can help
i have a possible faulty potterton thermostat with the twisty dial on the front and for the sake of a few pound i am going to replace it but i just want to confirm that i have got the wiring correct. so could any of your knowledgeable types confirm if i am correct

on the potterton thermostat rear i have 4 wires, red, yellow, blue and green yellow(earth)
all bar the earth are connected to the switch (the earth is connected to the box behind)

i have tried to list how they are connected below
diagram on switch cable colour
L terminal 1 red

* terminal 2 yellow

N terminal 4 blue

their are 2 terminal 4 and only one blue cable connected to the end hole

the new room thermostat is a drayton didistat +
and has 4 connectors marked Off, On, Com, N.
from what i can see i need to wire it up as

Off no cable
On yellow
Com Red
N Blue

The off connector is also marked heating satisfied or call for cooling
The on connector is marked call for heat

so could someone confirm if i am right
thanks in advance

[Badger0-0]

I would agree with that
Red has to be common, neutral Blue, and yellow is more than likely demand.
You'll soon know, as the stat will work back to front if the yellow is wrong

Easy way to test, turn the stat full down and if the heating comes on, it's wrong.

Seriously, I think you have it right

[carlymart]

Originally Posted by Badger0-0

I would agree with that
Red has to be common, neutral Blue, and yellow is more than likely demand.
You'll soon know, as the stat will work back to front if the yellow is wrong

Easy way to test, turn the stat full down and if the heating comes on, it's wrong.

Seriously, I think you have it right

thanks
will give it a try and with any luck it will work