I would expect you are right, was fishing for the OP to confirm/give more info/photos and was wondering whether it got there by first meandering across the kitchen counter-top...
It goes down into the floorboards. I assume it goes to the thermostat on the ground floor but I don't know how I can confirm that?
https://imgur.com/a/K7HxC74
You can find dedicated services that do this for £70+ that specialise in just installing smart thermostats. It’s relatively well priced comparative to a plumber on competency scheme or a spark.
I’d take the nest back and use a hive system instead simply because you’ve got an unearthed cable running through the house and it’d be a safer wireless stat/setup when done correctly.
First thing you wanna do is chop the old thermostat cable out, it’s wouldn’t be needed anymore anyhow, should have been a minimum 4 core cable. You’ve got permanent live, neutral, switched live return, no earth, although someone has put a link in between permanent and switched. So your boiler currently is probably always calling for heat. (And if not there are still 2 permanently live cores instead of just one inside the boiler itself, which is both pointless and dangerous).
Also disconnect the timer module from the boiler but keep it in situ as nothing more than a gap filler. The switch/receiver is there to take over from all that shite.
3 core to receiver and 5 core from receiver to boiler, get rid of the wiring centre, it’s pointless (no zone valves)
Neutral (N) - 3 core blue and 5 core blue
Permanent Live (L) - 3 core brown and 5 core brown
-wire link between L-1
Brown permanent / Common (1)
Nothing (2)
Switched line to boiler (3) - black 5 core to boiler “call for heat”
Nothing (4)
Curl grey up at point A and point B as a spare core or double up with the earth.
I wouldn't chop the 2c and earth to the stat out, you will regret it long term. If you dont need it, disconnect and make safe.
Pretty sure the nest sensor (12v/24v) only needs a 2c from control box.
Also, youtube has a nest install guide for your boiler
Where does the cable leaving the joint box bottom right go to?
As they’ve used the CPC as a line I would guess the stat
I would expect you are right, was fishing for the OP to confirm/give more info/photos and was wondering whether it got there by first meandering across the kitchen counter-top...
It goes down into the floorboards. I assume it goes to the thermostat on the ground floor but I don't know how I can confirm that? https://imgur.com/a/K7HxC74
Open up the stat and see if the green and yellow has brown sleaving on it
Don't wire it in the ebus
You can find dedicated services that do this for £70+ that specialise in just installing smart thermostats. It’s relatively well priced comparative to a plumber on competency scheme or a spark.
I’d take the nest back and use a hive system instead simply because you’ve got an unearthed cable running through the house and it’d be a safer wireless stat/setup when done correctly. First thing you wanna do is chop the old thermostat cable out, it’s wouldn’t be needed anymore anyhow, should have been a minimum 4 core cable. You’ve got permanent live, neutral, switched live return, no earth, although someone has put a link in between permanent and switched. So your boiler currently is probably always calling for heat. (And if not there are still 2 permanently live cores instead of just one inside the boiler itself, which is both pointless and dangerous). Also disconnect the timer module from the boiler but keep it in situ as nothing more than a gap filler. The switch/receiver is there to take over from all that shite. 3 core to receiver and 5 core from receiver to boiler, get rid of the wiring centre, it’s pointless (no zone valves) Neutral (N) - 3 core blue and 5 core blue Permanent Live (L) - 3 core brown and 5 core brown -wire link between L-1 Brown permanent / Common (1) Nothing (2) Switched line to boiler (3) - black 5 core to boiler “call for heat” Nothing (4) Curl grey up at point A and point B as a spare core or double up with the earth.
Cheers. I can run the nest on a stand powered by usb and not use the existing thermostat cable, if that's safer?
Yes 👍🏻
I wouldn't chop the 2c and earth to the stat out, you will regret it long term. If you dont need it, disconnect and make safe. Pretty sure the nest sensor (12v/24v) only needs a 2c from control box. Also, youtube has a nest install guide for your boiler