Google Nest Community

I bought a new nest to replace an old one which stopped working (https://www.googlenestcommunity.com/t5/Nest-Thermostats/Nest-learning-thermostat-stopped-turning-the-boiler-on/m-p/303582/emcs_t/S2h8ZW1haWx8dG9waWNfc3Vic2NyaXB0aW9ufExCQ1A5MFM5WFVDUUhE...

Hi,I have a nest learning thermostat which has been working ok* for a year and a half, and suddenly stopped turning the boiler on. The boiler is fine, I tried alternative wirings. Nothing works. The nest "looks" fine: turns orange when setting the te...