I have a nest that controls both heating and hot water from a condensing boiler.
It seems to randomly be turning on the hot water at 9pm despite the schedule not calling for it to be on. As far as the nest is concerned the hot water is off but the boiler is fired up, the pump working and the valve set to water.
I tested the system by turning on the heating when the system was running and the valve moved into the middle position and not the heating hence my conclusion that it must be a bug in the nest telling the system to come on.
Manually turning the hot water on and off does not resolve the issue, the only way is to cut the power and leave it over night. The following day the schedule works fine and it may not turn the hot water on at 9pm.
On days when it comes on at 9pm the schedule works fine and the hot water tuns off in the evening as planned. It then comes back on at 9pm and always 9pm, it would appear to continue all night if the power isn't cut
The scedule calls for 3 sessions each an hour long.
Hi there @Kucat,
Thanks for letting me know and thanks for the detailed explanation. That's very helpful. Could you tell me please if you go into Settings > Equipment > Continue > Bacteria Prevention in the actual thermostat, what option do you see highlighted in there?