HELP! replacing a thermostat

[scottishpete]

Ok just to update. Thanks everyone for the help. Boiler fuse was fine but no power getting to it. So traced down and found a fuse that fed the boiler and thermostat. A new addition when the previous owner installed the thermostat.

Replaced it and it blew again. Checked the wiring and put the old thermostat back on. Then replaced the fuse and it worked.

So.currently have old thermostat but everything working. I'll relook at the wiring and speak to an electrician friend to check the new wiring before confirming back here

 

[EFLImpudence]

All you have to do is with the left hand pair of Brown and Blue.

Brown to 1
Blue to 2

Right hand pair of Brown and Blue - NOT required.

Brown in a separate piece of connector block and position safely out of the way.
Blue to Park terminal.

 

[scottishpete]

Thanks. Just fitted and working! Hot water and heating. Thanks everyone for the help!

 

[EFLImpudence]

Very good. Thanks for letting us know.

For future reference -
Not all Blue or Black cables are Neutrals.

Wires can be used for whatever WE want.
They do not know what colour they are.