I have moved into a new house. It has an oil fired boiler. There is a Nest thermostat and heatlink to control the boiler. For radiators to work the hot water need to be on. Ordinarily when the Nest app schedule is triggered for water and heat the downstairs and upstairs radiators work. However, tonight the schedule stopped at 20:30 as expected. The radiators downstairs cooled down (not sure about upstairs at this point). Anyway on going upstairs at 22:00 the boiler is on and upstairs radiators are on and hot, but downstairs are off. The heatlink hasn’t been touched and indicates it isn’t on. It’s as though there are two zones, only we don’t have a second thermostat. There are two other Nest thermostats and corresponding heatlinks for two areas of electric underfloor heating but these are both off. Any ideas how this system might have been configured and how we can check if there are multi-zones?
