My Nest learning thermostat randomly switches my boiler on

[Bob99]

So I fitted my Nest learning thermostat in October and it’s worked pretty well with our central heating. However I’ve noticed that occasionally, in the middle of the day, the boiler will switch on for a while to heat water. I schedule water to heat once every morning from 5 thru 6am.  I’ve tried to reset and reprogram the device but it still randomly switches on. Tuesday around lunchtime seems to be a favourite although this is Thursday at 11am and I’ve just had it switch on again. 

Thermostat learning is switched off and the water temperature is fine. Is there some kind of hard reset I can invoke?

[AnaM]

Hey @Bob99,

Thank you for reaching out. Based on what you've described, it seems like it's just the hot water that's behaving strange. If that's the case, I'll kindly as you to check on the thermostat's display in Settings>  Equipment and Continue> Bacteria Prevention> turn Bacteria Prevention off and monitor the thermostat's behavior.  Bacteria Prevention is an exclusive feature of 3rd gen Nest Learning Thermostats. Bacteria Prevention mode will activate if your domestic water hasn’t been heated for at least 2 consecutive hours in the last 48 hours. This can happen if there is a gap of more than 48 hours in your hot water heating schedule or if you are away from home for longer than 48 hours.

[Bob99]

Thanks Ana. I’ve carried out another hard reset “Reset All” and will monitor this week to see if that’s resolved the issue. 

[DragosC]

Thank you. Keep us posted. 

[DragosC]

Hi there. I'm just following up on our last message. Do you still need our help? Keep us posted. 
 

[Bob99]

Today shld be the day to find out. It has a habit of switching on around lunchtime/ early afternoon. 🤞

[DragosC]

Thank you. No worries. Keep us posted. 

[george_t]

Hi @Bob99. How's it going with your thermostat? Does it follow your schedule?

[Bob99]

So after a hard reset of all settings and starting back up from scratch it seems the thermostat is now behaving itself. When booting back up the first thing I did, before programming a schedule, was to make sure all learning settings were set to off. I’ll continue to monitor but I think this has resolved the issue. 

[george_t]

I'm glad to hear that. Thanks for letting me know @Bob99. As you mentioned, you can monitor the behavior of the thermostat for a few days, then tell me how it works and if you need any further help.

[DragosC]

Hi there. I'm just following up on our last message. Do you still need our help? Keep us posted. 
 

[AndaD]

It's been a while since this thread was last updated so I'll go ahead and lock this thread. If you're still experiencing problems, please feel free to start a new thread and we'll be happy to help.