Sunray you absolute legend. I carried out your instructions and it's worked perfectly; the ugly old timer is now off the wall and the boiler responds to the wireless thermostat just fine without it. Bless you!
Out of interest, wire number 5 is indeed the same as wire number 6, but it goes...
Thanks both of you, appreciate you taking a look - here's the view behind the blanking plate.
I must admit my first thought is "crikey where do I start" - but then I'm no sparky so maybe this is easier than it looks to me...
I've an old Danfoss wall timer which at one point in time controlled the on/off of the central heating to my combi boiler. Photos attached.
For about 5 years I've had no use to touch it as I've since had a wireless thermostat installed. (There's a receiver for that hooked into the boiler, and a...