Ok I have the thermostat you linked to @JSHarris on the other thread

https://www.screwfix.com/p/drayton-rts3-24003sx-frost-thermostat/9578r

but could really do with some help in how to wire it up. 

so I have a DIMPLEX WALL-MOUNTED TUBULAR HEATER 80W or something very similar  with a uk 3 pin  plug on it 

 

I have a spare socket in my water treatment cupboard that is outside but insulated and totally weather proof. 
 

I want to wire in the thermostat so that the heater comes on when the temp drops below 3 degrees (the heater does not have a thermostat)

 

can someone draw me a simple diagram of how this is meant to work as I am having a bad day and struggling to get my head around it.....  and need to get this job done ASAP as I am leaving in a week and don’t want to leave the system vulnerable to freezing. 
 

thanks ! 
 

p.s Long day, tired and confused and want to have a go tomorrow morning when I am fresh. 

 

 

 

The connections on the thermostat are neutral, line in and switched line out (terminal 3).

 

Connect the incoming neutral (blue) to the N terminal, and also to the heater neutral (either cut the plug off or add a single gang outlet wired to the thermostat).  The incoming line (brown) goes to the thermostat L terminal and the thermostat terminal 3 connects to the line on the heater (or the socket, if you opt to wire it that way).

 

The supply that goes to the thermostat needs to be fused or otherwise protected to match the size of cable used in this case.   You can either choose to wire it up to a lead with a 13 A plug, using a 3 A fuse, or you could wire it to a switched fused connection unit, also with a 3 A fuse.  Make sure the incoming earth connects to the heater (there's no earth on the thermostat).

 

Thanks, I think I will be good to go tomorrow. 

It’s amazing what a Fresh start on a new day can do for the head....  wiring was easy, i was confused about the earth but @JSHarris diagram made it easy. So I still need to shorten some wires, do a bit of tidying up, plastic caps on the roof screws.... but it’s all in and ready for council inspection on Thursday and then I am away the next day for two months so hopefully it will all work flawlessly while I’m gone......  right 150 meters of blue pipe to dig in today...... 

Love the bottle funnels ..!!! Just as belt and braces, I would put a plastic shield over the top of the plug socket panel and seal to the wall in case water somehow gets in there. 
 

Lovely tidy job there though !!

1 hour ago, PeterW said:

Love the bottle funnels ..!!! Just as belt and braces, I would put a plastic shield over the top of the plug socket panel and seal to the wal

Ha the funnels were your idea I think and they work really well, good point on the extra  cover over the electrics, I had added the black plastic below the roof as a secondary protection from above just in case some how water tracked back from some unknown location behind the roof.... but it would be easy to cover the electrics specifically as well just in case a small leek was to spring and somehow get in there, will do it before I go. Thanks for the tips.