Thermostat not controlling heating system

[PARA123]

My central heating stopped working and I traced the fault to the thermostat. I have replaced the thermostat (Drayton RTS1) and the system still won't turn on. I have tried turning the dial through the full temperature range and I don't hear a click! I can bypass the thermostat by connecting the cables L and 3 (Common + Call for heat) and everything works correctly.
Any idea's why the thermostat isn't working?

 

[IanDB]

Are you getting 230v at the thermostat? It won't work without power.

 

[PARA123]

I haven't specifically tested for power. If no power is detected, what are the likely causes bearing in mind everything else is working correctly.

 

[IanDB]

That's a good question!! The power comes either from a terminal in your boiler or programmer depending how it's wired. There's nothing else in the way. There was a previous post with diagrams (although not Drayton but the principle is the same), see here //www.diynot.com/forums/viewtopic.php?t=7973.

You could also have been just plain unlucky and got another u/s thermostat but I think that is unlikely.

 

[CH4]

The Drayton RTS1 thermostat has an electronic sensor. In addition to the Live connection, it also requires a Neutral connection to function. Check the continuity of the Neutral wiring.

Alternatively, a Drayton RTS7 thermostat can be used in 2 wire CH heating systems (where there is no Neutral).

 

[PARA123]

I checked the power and could detect a decent reading from live. I then ran a continuity test on the Neutral wire and this failed. I then replaced the wiring from the controller to the thermostat and hey presto its all now working!! Many thanks for all the input.