We've had a Nest Third Generation Thermostat since 2017, which I installed myself, and was working perfectly until we took it with us when moving house earlier this year.
Despite the boiler at our new home being identical (with everything correctly wired in), it isn't taking any instructions from the Nest at all, instead remaining constantly powered with the heating turned on.
As it had previously been working fine, I'd assumed this to be an issue with the boiler, but two separate heating engineers have now looked at it and insisted that it can't be, as the fact that the heating is working means that the loop is complete, therefore pointing at the thermostat, but I can't seem to find any record of a similar problem online.
The heat link powers up correctly, is showing a green light, and I can hear the switch turning on and off when either adjusting the temperature dial or turning it on manually, so it doesn't seem to be a connectivity issue in that respect.
Are there any known issues with the Nest that might cause this? Is there anything I can be advised to do to isolate what exactly the problem is?
