It is yes.
OK, thanks for you help.
Good news is... I didn't break it.
Bad news is... heating doesn't work!
I'm glad I got to this now before the cold weather arrives.
Thanks for that.
Just popped an image on above with a bit of an update.
Wondering if it is just the heating itself and was unrelated, as you suggested.
Here you go.
I connected red to yellow; left blue out of the equation.
Update though... pump has stopped now. I turned all power off again for a bit; when power was back on (with old thermostat still connected), pump started and then went off after a few minutes. Guessing this is normal after...
We have a Hive thermostat controller and have done for a while. I've decided it was time to remove the old thermostat from the wall in the utility. (Since we got Hive, it's always been set to max temp so always on, as such, leaving Hive to do the hard work.)
Removing the thermostat, I hooked up...