propex thermostat replacement again

[kevtherev]

mine was right at the back not visible unless the whole thing was dismantled
it was hard wired in.

[Doctor Foster]

Ok some pics.

Existing thermostat

[Doctor Foster]

Existing thermostat wiring diagram

[Doctor Foster]

New thermostat with wiring diagram and existing thermostat with wiring diagram

[Doctor Foster]

Kev, Is the terminal marked number 2 on yours the wire from the switch??

OK the two earths are connected together and they connect to a diode of some sort which then goes to No.1 along with one of the live feeds
the other live goes to no.2

No. 3 is empty

now this is electrickery at it's most baffling.

but... all I did was use the old thermostat as a template to wiring it to the new one

[kevtherev]

yes it is

[Doctor Foster]

hmm the new thermostat connections are proving to be tricky. I have sorted the new switch so have 12v in to the new thermo. Just trying to figure out which terminal is 'L'

The resisitor between the red and black? What does that do??

I have tried different connections and have got the new thermo to switch the propex on when it is turned down near 0.

Im wondering If I have the wrong type of thermostat

[Doctor Foster]

Nope still no joy


Kev, what make and model is your thermo??

[VWCamperfan]

Just to help out a bit (if it does!). The new thermostat connections for making a circuit when cold enough are connections 1-(common) and 3-(demand).
The connections 1 and 2 are made when the temperature is hot enough... 1 and 3 when its become too cold and the thermostat switches on.

Just a thought though, Ermie571 (Emma), bought one of these thermostats, exactly the same and it didn't work when connections 1 and 3 were closed. You could physically see the connections come together but there was no connection according to the multimeter. Had to clean the connections but it still seems a bit suspicious at times. This was straight out of the box too, not good!

The other connections on the switch aren't used as they are for a mains lamp that comes on when in use.

[Doctor Foster]

Just to help out a bit (if it does!). The new thermostat connections for making a circuit when cold enough are connections 1-(common) and 3-(demand).
The connections 1 and 2 are made when the temperature is hot enough... 1 and 3 when its become too cold and the thermostat switches on.

Just a thought though, Ermie571 (Emma), bought one of these thermostats, exactly the same and it didn't work when connections 1 and 3 were closed. You could physically see the connections come together but there was no connection according to the multimeter. Had to clean the connections but it still seems a bit suspicious at times. This was straight out of the box too, not good!

The other connections on the switch aren't used as they are for a mains lamp that comes on when in use.

Thanks for the info. Have you got a basic wiring diagram at all??

[Oldiebut goodie]

Your problem is most probably that you are using an item that is expecting 230 volts and only giving it 12 volts! You need a dedicated 12 volt one or a purely mechanical one.

E D I T to add
Noticed that your old one is 24 volt - are you running at 24 volts? If not maybe that is why it doesn't work correctly!

[Doctor Foster]

Your problem is most probably that you are using an item that is expecting 230 volts and only giving it 12 volts! You need a dedicated 12 volt one or a purely mechanical one.

E D I T to add
Noticed that your old one is 24 volt - are you running at 24 volts? If not maybe that is why it doesn't work correctly!

I realise that its made for 24-240v

I was aware that they can be modified to run on 12v. Perhaps Im misinformed.

[Oldiebut goodie]

I know that a 230 volt one will not work on my 24 volt Webasto.

[Doctor Foster]

Ok. Thanks for the info Oldie.

I think Im gonna bite the bullet and purchase a proper one from Propex.

[kevtherev]

Your problem is most probably that you are using an item that is expecting 230 volts and only giving it 12 volts! You need a dedicated 12 volt one or a purely mechanical one.

E D I T to add
Noticed that your old one is 24 volt - are you running at 24 volts? If not maybe that is why it doesn't work correctly!

mechanical thermostats are just switches they require no power to make them work.
if you didn't connect it to anything it would switch on and off as the temp rose and fell past the set temp

mine is a room thermostat and works perfectly well.
Sunvic is the name of it

like this one
http://www.sunvic.co.uk/tlx2000_series.htm" onclick="window.open(this.href);return false;