Thanks for the quick reply!
I'm glad it's not just me who that the extra wire was odd. I'll trace it back tonight when i get home and post a pic if I can, and check if L is linked to 1 but I'm fairly sure it isn't.
There's no existing room stat - the boiler is in the loft and has an old...
Hi!
I'm about to replace an old timer with a wireless thermostat.
I've taken the old one off the back plate and see 5 wires attached.
The installation diagram for the new one shows only four attached wires.
Looking at the diagrams do I attach the extra wire (currently on 2, off)...