I have a nest thermostat which was installed around 2019. Just recently I got a H71 error on the thermostat. I checked the heat link and see it is totally dead, no lights. Tried to reset but not working. I've checked the fuse board and also an isolator switch on the heating system and both are functioning so there is power going to the unit but it's completely dead.
Does anyone have any advice on how I sort this. Supply and installation was through an electrical in Irelans. Obviously I want to try and sort while the weather is mild
