How do I wire a frost stat to a tube heater

[sealegsjim]

I have just bought a 240v 120W tube heater with standard 3 core flex and plug and a frost stat which I intend to use in the engine compartment plugged in to shore power mains. The frost stat has only a very simple diagram with no instructions and I am not really sure how to wire it. I have included the wiring diagram, Can anybody help please?

 

[VicS]

It appears to show the wiring for a motorised (Spring return ? ) valve.

Just wire it with the heater in place of the motorised valve!

A bit puzzled though that it appears to use the normally closed contacts rather than the normally open.
If the heater switches off when it should come on an vice versa use terminal 3 instead of terminal 2

 

[sealegsjim]

It appears to show the wiring for a motorised (Spring return ? ) valve.

Just wire it with the heater in place of the motorised valve!

A bit puzzled though that it appears to use the normally closed contacts If the heater switches off when it should come on an vice versa use terminal 3 instead of terminal 2

I realized that the 'M' was the load ie the heater; but in practical terms how do I actually wire it and why does the connection 'cooler' appear to go nowhere. Sorry for my ignorance

 

[VicS]

The 'stat is a change over switch. One pair of contacts is normally open and the other normally closed.

You need to use the pair that close, and switch the heater on, when the temperature falls to what ever temp is set.

The other could be used to switch a cooler on if the temp rose above the setting

 

[sealegsjim]

The 'stat is a change over switch. One pair of contacts is normally open and the other normally closed.

You need to use the pair that close, and switch the heater on, when the temperature falls to what ever temp is set.

The other could be used to switch a cooler on if the temp rose above the setting

Many thanks for that VicS; I really appreciate your taking the time to clarify it. Thanks I shall try it out tomorrow

 

[dingdongs]

how about one of these;http://cgi.ebay.co.uk/TIMEGUARD-ET0...al_Electrical_Fittings_MJ&hash=item3cb33e4dfe

 

[gasdave]

how about one of these;http://cgi.ebay.co.uk/TIMEGUARD-ET0...al_Electrical_Fittings_MJ&hash=item3cb33e4dfe

I'm using something similar with my 4' tube heater (I think nearer 200Wish IIRC), currently set at 12 degrees. Very simple.
Last time I was at the boat (still in water) it was covered in snow and working very well inside - no damp, frost, condensation, etc.. In fact almost cosy inside! 26' boat, engine bay open to cabin for circulation.