NEST switching on automatically even when auto scheduler is set to off

guessaname · 29-11-2017 10:54am #1

Hi,

[font=arial, sans-serif]I got NEST thermostat installed by ElectricIreland recently. My system two zone (heating and hot water). I have set my thermostat for both heating and hot water to run on scheduler. I have disabled auto-schedule, NEST sense, home away etc to make it in run only on the scheduled time. The problem is I have noticed that my NEST is switching on the boiler to heat the water automatically at random times even when the NEST scheduler is set to off at that time. I have disabled the NEST sense and auto-scheduler but still its switching on the boiler at random times. Another thing is when it switches on the boiler automatically the NEST thermostat is not displaying that the hot water is on. I think its something wrong with either the heat link or thermostat that are switch on the boiler out of schedule. I would like to get this fixed coz its costing me the money to unnecessarily heat the water when its not required. Could you please help me to fix this? Can I PM you my details?[/font]

[font=arial, sans-serif]Thanks [/font][font=arial, sans-serif] [/font]

Electric Ireland: Una · 29-11-2017 11:37am

Hi guessaname,

Sorry to read of the technical issues you are experiencing with your Nest thermostat.

Here in the Social Media department, we do not have access to the Home Services system so we recommend contacting the Home Services team directly on 1850 372 333. Their telephone lines are open until 6pm Monday to Friday (excluding public holidays). They will have the information to advise you regarding your query.

Regards,
Una

ADSLUSER · 29-11-2017 12:02pm

Sounds like your Nest is in pre-heat mode - i.e where it learns your heating patterns and switches on earlier (pre-heat) to meet the desired temperature at the time you scheduled. For more information on this feature, see: https://nest.com/support/article/What-is-Early-On

guessaname · 29-11-2017 2:24pm

Is it called True Radiant in 3rd gen NEST? Its set to off on my thermostat. Again the thermostat or heatlink is switching on the boiler at random times. My scheduler is programmed to start heating (both hot water n radiators) from 18:00-19:00 which it did but automatically switched on the water heating (not the radiators) at 23:10 for no reason. day before yesterday it started at 22:00.

ADSLUSER wrote: »

Sounds like your Nest is in pre-heat mode - i.e where it learns your heating patterns and switches on earlier (pre-heat) to meet the desired temperature at the time you scheduled. For more information on this feature, see: https://nest.com/support/article/What-is-Early-On it

ADSLUSER · 29-11-2017 2:27pm

Yes, for Gas Boilers and radiators- the feature is called True Radiant. I find the feature quite useful but you can switch it off if you prefer strictly scheduled on/off mode. More details here on how to customise your True Radiant settings: https://nest.com/uk/support/article/How-to-change-True-Radiant-settings

Skatedude · 29-11-2017 2:47pm

Is it possible that it's switching on for anti freeze protection? a lot of heating systems will turn on automatically when temperatures drop to near freezing to prevent pipes from icing up.

ADSLUSER · 29-11-2017 2:53pm

That could be the case too. You can set the "Safety temperature" to a certain temperature setting. For example, I think by default it's set to 4C to turn on which would prevent pipes from freezing over. You can adjust this in your App from Settings -> Equipment -> Safety temperature.

guessaname · 29-11-2017 2:54pm

Skatedude wrote: »

Is it possible that it's switching on for anti freeze protection? a lot of heating systems will turn on automatically when temperatures drop to near freezing to prevent pipes from icing up.

mmm that makes sense. Its switching on the water heating only though and also the house is usually warm during those hours at night. unless its taking the outside temperature into consideration and starting the boiler.

ADSLUSER · 29-11-2017 3:00pm

I have a Nest Gen 2 and my boiler doesn't support just water heating so it's possible that's what your Nest is doing. The only other possible explanation is if you have the Nest learning mode switched on and for whatever reason it's turning on at those times. Did you check your schedule to see if Nest added anything to it?

guessaname · 29-11-2017 3:08pm

ADSLUSER wrote: »

I have a Nest Gen 2 and my boiler doesn't support just water heating so it's possible that's what your Nest is doing. The only other possible explanation is if you have the Nest learning mode switched on and for whatever reason it's turning on at those times. Did you check your schedule to see if Nest added anything to it?

Nest learning mode is switched off and auto-scheduler is also switched off. When I check the history of energy usage on the thermostat its not displaying the energy usage during the hour when it started automatically. All I can see in the energy history is during the time I set in the scheduler (18:00-19:00). Weird thing is when it started the boiler automatically at 10 pm yesterday both thermostat and app wudn't show (screen doesn't turn orange) that water heating is on. It just displays Hot Water off till 18:00 (i.e next day 18:00).

ADSLUSER · 29-11-2017 3:26pm

Hmm that doesn't sound right. The status on the Nest will/should always reflect if the boiler is on or off and also capture this record in the history. This includes any pre-heating of true radiant modes. I wonder if your boiler has any other override controls which is outside of Nest?

ADSLUSER · 29-11-2017 3:26pm

Hmm that doesn't sound right. The status on the Nest will/should always reflect if the boiler is on or off and also capture this record in the history. This includes any pre-heating of true radiant modes. I wonder if your boiler has any other override controls which is outside of Nest?

ThisRegard · 29-11-2017 3:31pm

If it's coming on at seemingly random times and not showing that either the heating or water is on, it sounds like the bacterial prevention mode. It doesn't appear in your history either.

https://nest.com/uk/support/article/How-does-the-Nest-Thermostat-help-prevent-Legionella-bacteria

Is the Nest itself showing a little yellow with black water drop icon like here? It doesn't turn your screen or app orange like it normally would when heating either the radiators or water.

https://pbs.twimg.com/media/CV5dd07WUAA9f6r.jpg

kennethsmyth · 29-11-2017 3:36pm

This regard is probably right - i've switched off the bacteria mode as my hot water tank has a thermostat on it set to appox 60/65 and so this cuts off the boiler if the scheduler on nest keeps going past that water temp. If its not that check if the hot water is going on as per your heating schedule and visa versa - ie has it been wired up backwards!

guessaname · 29-11-2017 3:36pm

I still have a manual/wired thermostat on the wall in the hall. Its set to 21C. Never touched it. I used have a manual scheduler near the boiler which was replaced with NEST by electric Ireland installer. Does this thing have any impact on the boiler (or NEST)? We never had any issues with the previous manual scheduler.

ADSLUSER · 29-11-2017 3:36pm

That could be it - seems like a new feature for Nest 3rd Gen however I'm still surprised it doesn't register in the history. In any case, it's worth checking to see if this is enabled or off?

guessaname · 29-11-2017 3:42pm

ThisRegard wrote: »

If it's coming on at seemingly random times and not showing that either the heating or water is on, it sounds like the bacterial prevention mode. It doesn't appear in your history either.

https://nest.com/uk/support/article/How-does-the-Nest-Thermostat-help-prevent-Legionella-bacteria

Is the Nest itself showing a little yellow with black water drop icon like here? It doesn't turn your screen or app orange like it normally would when heating either the radiators or water.

https://pbs.twimg.com/media/CV5dd07WUAA9f6r.jpg

But it says "The 3rd-gen Nest Thermostat’s Bacteria Prevention mode will be activated if your domestic water hasn’t been heated for at least 2 consecutive hours in the last 48 hours."
My one heated the water and radiators from 18:00-19:00 and started heating the water automatically at 22:00. We didn't even use the hot water much during that time. I'm sure the tank was full of hot water around 22:00 when it started again.
Any possibility of incorrect heatlink wiring or something? Any way to reset the whole system (heatlink n NEST)?

ThisRegard · 29-11-2017 3:53pm

guessaname wrote: »

ThisRegard wrote: »

If it's coming on at seemingly random times and not showing that either the heating or water is on, it sounds like the bacterial prevention mode. It doesn't appear in your history either.

https://nest.com/uk/support/article/How-does-the-Nest-Thermostat-help-prevent-Legionella-bacteria

Is the Nest itself showing a little yellow with black water drop icon like here? It doesn't turn your screen or app orange like it normally would when heating either the radiators or water.

https://pbs.twimg.com/media/CV5dd07WUAA9f6r.jpg

But it says "The 3rd-gen Nest Thermostat’s Bacteria Prevention mode will be activated if your domestic water hasn’t been heated for at least 2 consecutive hours in the last 48 hours."
My one heated the water and radiators from 18:00-19:00 and started heating the water automatically at 22:00. We didn't even use the hot water much during that time. I'm sure the tank was full of hot water around 22:00 when it started again.
Any possibility of incorrect heatlink wiring or something? Any way to reset the whole system (heatlink n NEST)?

That's not two consecutive hours though. That's two separate heating periods. How long is it on for at 10pm? It needs to be on for at least 2 hours non stop for it not to kick in.

guessaname · 29-11-2017 4:00pm

I didn't let it run for long yesterday at 10 pm. I switched the hot water off (using the app Hot Water - > Settings -> On/Off) after 10 mins it started. Nest was installed last month and we never ran the hot water continuously for 2 hours (I mean using the scheduler). Its scheduled to run 10:00-11:00 and 18:00-19:00 on weekends and 18:00-19:00 on weekdays. Whenever we need the water urgently we boost it for 30 mins. Now I think it makes sense that its trying to heat it up to kill the bacteria. I will let it run today if it starts automatically and see how long it runs.

ThisRegard · 29-11-2017 4:06pm

If you notice it starting it again take a look at the Nest display to see if it's showing that icon anyway.

We never have our water heating for 2 hours and I did wonder myself what was going on first time I noticed it.

TBH I don't even know if we need that function anyway, Rare you hear of incidences of that bacteria in residential homes that are lived in normally.

guessaname · 29-11-2017 4:13pm

Sure I will check that today. Hope its as simple as automatic bacteria prevention feature and nothing major like wiring related stuff. Thanks a million for all your help ThisRegard and ADSLUser.

guessaname · 30-11-2017 1:42pm

Hi I have disabled the bacteria protection and it didnt start automatically yesterday. electric ireland sent these instructions for my query. thanks for ur replies n help guys.

Please follow the below instructions and this should stop the hot water turning on when it is not meant to

1. Press your thermostat ring to bring up the Quick View menu.

2. Select Settings.

3. Select Equipment and Continue.

4. Choose Bacteria Prevention.

5. Here, you can enable or disable Bacteria Prevention.

Fingers Mcginty · 24-01-2019 9:13am

sorry for replying to old thread but I've had this issue also I [font=Roboto, Arial, sans-serif]had previously had an issue with the hot water motorized valve going bad (bad spring/position sense) i went down the wrong road of trying to diagnose it. When i removed the actuator i was expecting the spring to release it back to the closed position but it didn't indicating power was being supplied to the motor to keep the valve open. So the heatlink was trying to keep the valve open.[/font]
[font=Roboto, Arial, sans-serif]Even though it was not scheduled to in my app.[/font]
[font=Roboto, Arial, sans-serif] So i checked the nest thermostat and there was a little yellow icon with a black drop indicating bateria mode. What i coulon't understand though is i have the schedule to run hot water for an hour in the morning and an hour in the evening so the tank would have been hot but i suppose it wouldn't have been two "consequitive" hours. I will now switch it off. [/font]

Electric Ireland: Aoife · 24-01-2019 10:18am

Hi there,

Thank you for getting in touch.

This may be a query for Nest directly but our colleagues in Home Services team may be able to give you some advice.

Our colleagues in Home Services department can be contacted by phone on 1850 372 333 (9am-6pm Monday - Friday), via Live Chat or via email on homeservices@electricireland.ie.

Should you have any other questions, please don't hesitate to ask.

Thanks,
Aoife

NEST switching on automatically even when auto scheduler is set to off

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