Water scheduled enabled but water does not always heat on schedule

[bambunclody]

I have a 3rd generation Nest thermostat and since  it was installed I have problems with the water heating controls. I have a schedule set but the water does not heat on schedule after perhaps 2 or 3 3 successful scheduled times. 

Other people have told me to turn off Bacteria Prevention in the thermostat - which I have done on numerous occasions . The schedule will work perfectly for 2 days or so then revert to not heating the water except by boot. It is really annoying and despite the amount of money I paid for google nest, I am seriously considering replacing it with a system I can rely on. To wake on a winters morning to a cold shower because of a defect in the thermostat is not something I intend to do on a regular basis. Google needs to sort this out.

[AlexD]

Thank you for reaching out to us here @bambunclody . I am sorry to hear you are facing difficulties with your device and I would be happy to try and assist. Let's check a few things and see if we can figure out what's going on.

1. How long has the thermostat been installed for?

2. Was it installed by a Nest Pro installer or a regular installer?

3. Do you happen to know if you have a Y plan valve system or a S plan valve system installed at the location for heating and hot water?

4. Please also take a screenshot of the hot water schedule so we know what the expected behavior would be from the thermostat. 

[bambunclody]

1. I had the Google nest system installed by a local electrician more than a year ago. Last March, the thermostat stopped working and google gave me a replacement. The problem has only started  since the replacement thermostat was connected. The system was working well until the first thermostat failed.

2. It was installed by a regular installer.

3. I have no idea what you are asking - here. As I said the google system worked well until the first nest thermostat failed.

4. I have the water set to come on weekdays from 6 to 7.30 am and 5.30 to 6.30 p.m. and weekends from 7.30 to 9 am and 6 - 7 pm.

It failed to heat again this morning until i pressed boot.

[DragosC]

Thanks for letting me know. Could you provide me with a picture of the Heat Link's wiring? 

[george_t]

Hi @bambunclody. Just checking in, did you manage to read my colleague's message?

[bambunclody]

I read the message, but I haven't sent a photo of the heat link wiring. 

The water heating worked as scheduled on the previous thermostat (that thermostat failed completely  to work in March 2022). Nest replaced this thermostat and the water heating on schedule has just become a problem since then. I am not an electrician and I am not inclined to open the heat link to expose wiring.

On other fora I have noticed that people had this same problem. Google Nest must have a solution or tell us that the don't so I can replace a faulty system with one that actually works as I need it to.

[george_t]

I understand, but for us to understand the issue better it would help. Also, please let me know if you have the Auto-Schedule setting on? You can check that into Settings -> Nest Sense -> Auto-Schedule.

[bambunclody]

Yes, the Auto-Schedule is on

[DragosC]

Thanks. Now, please go into settings > Equipment > Continue > Bacteria prevention and send us a picture from there. 

[bambunclody]

Bacteria prevention is disabled.

[DragosC]

Does it say "Disable" or "Enable" ?  

[bambunclody]

Enable

[DragosC]

Thanks. Could you please check on the wiring? Could you provide us with a picture of the wiring underneath the Heat Link's case? 

[bambunclody]

[Vladut]

Hi there, thank you so much for reaching out. It seems that I cannot see anything attached. Can you please resend it?

[bambunclody]

[Vladut]

Are you near the thermostat at the moment?

[bambunclody]

No I'm not.

[AlexD]

When you are let us perform a click test using the Nest app. Go to the Hot water control section and tap on the cogwheel in the upper right corner to go into settings. There you should have the first toggle enabled, turn it off.

1. Once done, boost the hot water and listen for a clicking noise from the Heat Link.

2. Stop the boost and listen for a clicking noise again. 

Let me know if you heard a click each time or not. And make sure to set that toggle back to on once done. 

[bambunclody]

It clicked  as I was changing the settings but not when I was exiting from that mode.

[bambunclody]

Once again this morning the hot water failed to heat on schedule although I went through all the steps as outlined by AlexD, Vladut and DragosC.

It is most frustrating to have purchased an expensive item, which then does not work as advertised, especially when it means waking to a cold shower in winter.

[Vladut]

Hello @bambunclody, that's a strange behavior indeed. Can you tell me if you've tried to reset the thermostat to factory defaults?

[bambunclody]

No, I haven't tried that. I will do so when I return home.

[AlexD]

Thanks for trying. Keep us posted with the behavior. 

[AlexD]

Hi, I wanted to check in. Make sure to let us know here how it goes once you try to reset the thermostat.

[AlexD]

Hey there, I haven't heard from you in a while so I'll be locking this thread. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community. Thanks, AlexD.