Unscheduled Hot Water Heating

[MarkR61]

I have my hot water scheduled to come on twice a day; 6-8am and 5-7pm.  However I have noticed that the hot water is being heated outside these times, always around 3pm in the morning.  The strange thing is the thermostat says the hot water is ‘off’, but I know it isn’t as the boiler is fired up and indicating it’s heating the water in the cylinder.  I’ve had the installer out a couple of times and the only solution that cures it is a ‘factory reset’ of the thermostat.   Whilst I now know how to do the reset myself, it’s seems to be happening pretty frequently, not that I’m up checking it at 3am every day, and I’m concerned about the wasted energy costs. Just wondered if anyone else has experienced the same issue?

[AndaD]

Hey there @MarkR61, thanks for reaching out. We're here to help. Could you tell us when it started happening? Is this issue related to the initial installation? Also, what country are you located in?

[MarkR61]

The Nest installation was installed about 2 years ago and I first started to notice the issue about 6 months ago. Mostly comes on outside of the schedule in the early hours, but having said that I’ve noticed it on in the daytime more recently.  A factory reset of the thermostat seems to stop it for a couple of days, but then it starts to do it again.  I am in the UK.  I’m thinking the only solution is a new thermostat.

[AndaD · Accepted solution]

@MarkR61 Thanks a lot for the details. No worries — I am here to help. Let's check a few settings on you thermostat:

1. Press the thermostat ring to bring up the Quick View menu
2. Select Settings 
3. Select Equipment and Continue.
4. Choose Bacteria Prevention.
5. Check if it is enabled. 
6. Select disable Bacteria Prevention.

Let me know if you manage to do it. 

[Vladut]

Hi there, just checking in with you. Did you manage to check the above steps? Keep me posted.

[MarkR61]

I’m away still, but will check and let you know in a couple of days 👍🏼

[Vladut]

No worries. Please ping me when you've done it!

[MarkR61]

Right I’ve reset my thermostat and on checking the bacteria prevention setting it was ‘enabled’ - I’ve done as you suggested and set it to ‘disabled’.  I’ll keep an eye on it to see if that now stops heating the water outside of the set daily scheduling. Fingers crossed and thank you for the advice 👍🏼

[DragosC]

Thank you very much for letting us know, @MarkR61

Keep an eye on it and keep us posted. Have a good one! 

I'll have to close this thread. Should anything else come up, please open another thread and we'll take it from there. Have a good one and stay safe!