Schedule Nest for below 9°C minimum temperature

[YB-Brighton]

Schedule Nest thermostat for below 9°C minimum temperature....  this is impossible?

My understanding is that Nest thermostats cannot be programmed to turn off/on at given times, they must be constantly on and then can be configured for specific temperatures at specific times.

Basically I only want to set the heating to come on two hours every day, and the workaround for this is to set the base temperature very low - in effect, turning it 'off' because the ambient temperature will not fall sufficiently low to trigger the radiators to turn on (unless the weather is extremely cold, in which case the frost protection will kick in or I will temporarily set the temperature a bit higher to be on the safe side).

Eco temp is set to 4.5°C, safety temperature is set to 4.5°C.

For 22 hours out of every 24, I will need to set the minimum temperature throughout the winter to 4.5°C to prevent the pipes freezing, but anything above that is excessive and expensive, never mind the environmental impact.

If I want to maintain the base temperature at 4.5°C minimum, my only option is to set the heating to OFF and manually turn the heating on when required.

If I want to create a schedule for heating to come on, my only option is to set the heating to ON which means the temperature is 9°C minimum and the radiators will keep firing up.

So I either waste money/energy or have to remember to switch the heating on and off at the appropriate time (I set an alarm on my phone at the moment).

Google Nest phone support have basically told me "tough, you can't schedule below 9°."

Although Nest is a smart thermometer, I have turned all the smart functionality off and am using it in 'dumb mode' (don't ask why, it's too boring). It is being used in a commercial environment, not a domestic setting so nobody is sleeping in the building, no pets or anything (again, don't ask, this wasn't my decision). The warmest it needs to be for the majority of the time is 4.5°C.

Has anyone got any suggestions other than rip it out and replace with something else?

[GBD]

The Nest thermostat has a safety temperature setting (I believe the default is 4.5c) and if the temperature falls below this, the thermostat will run the furnace even if it is set to off.

https://support.google.com/googlenest/answer/9249790?hl=en-CA#zippy=%2Cset-safety-temperatures

[YB-Brighton]

Thanks for the reply! Sorry if my question wasn't clear. Yes, the Nest thermostat has a safety temperature setting and yes, you are absolutely correct that the default is 4.5c. 

"Eco temp is set to 4.5°C, safety temperature is set to 4.5°C."

However, I cannnot set the scheduled temperature to be 4.5°C. The lowest I can set the scheduled temperature to is 9°C which is too warm.

The minimum scheduled temperature I can set is 9°C, which is twice as much as the safety temperature.

It's not a house so I don't want to pay to keep it warm like a dwelling, I just want to schedule the minimum temperature 4.5°C to keep it from freezing. If I had my old click-and-dial Honeywell thermostat, this would be possible but apparently not with Nest??

[GBD]

Maybe I wasn't being clear either. What I'm trying to say is to just turn the thermostat to the off setting. The thermostat will maintain that safety temperature even if it's off.

[YB-Brighton]

BTW if I want the temperature to be 4.5°C minimum constantly, the workaround is simple - just ensure Eco temp is set to 4.5°C, safety temperature is set to 4.5°C and then turn the thermostat OFF in the app. Unless the outside temperature plummets, the radiators will definitely not come on.

The issue is that I want to schedule the minimum temperature to be 4.5°C for 22 hours between 13:30 and 11:30, and then schedule the minimum temperature to be 20°C for 2 hours between 11:30 and 13:30.

[GBD]

Ah, now I get it. You certainly can create a routine in the google home app to turn the furnace on at your desired time and then another one to turn it off at your desired time. Alternatively, you could use the script editor at home.google.com to create a routine that does it all in one script.

[YB-Brighton]

Does that make sense? The Nest will not run any schedule when the thermostat is off, so I can't schedule anything between the parameters of 4.5°C and 20°C. It will only allow me to schedule between the parameters of 9°C and 20°C. 

[YB-Brighton]

Thanks again for your help! I'm trying to do something very specific here rather than run the Nest system as it was probably intended to work, but it's a set-up I've inherited rather than something I would have chosen for myself.

[GBD · Accepted solution]

This will create a schedule for turning it on not in the thermostat but rather in Google Home. It also assumes that you have your thermostat setup with Google Home.

In your google home app, select Automation along the bottom.

Select the + to add a new automation,

Select Personal,

Select + Add starter,

Select At a specific time and set your time and days of the week to run,

Select Add starter

You should now have a routine set to activate at your desired time and now to add the what you want it to do.

Select + Add action

Select Adjust home devices

Scroll down to find your thermostat and select it.

Select the Change setpoint checkbox and move the slider to 20c

Select the Change mode and the select Heat.

Select Add action

The routine we are creating will now change the furnace from off to on and ensure it's set to 20c. Now to turn it off after one hour.

Select + Add action again

Scroll down to the bottom and Select Delay start.

Set the delay for 1 hour

Select the + Add action (The one after the After 1 hr delay we just added)

Select Adjust home devices

Scroll down and select your thermostat.

Select Change mode and set it to off

Give your routine a name and select save. Now Google home will, at your set time and days, turn the thermostat from off to heat and make sure it set to 20c, The routine will perform no further actions until after the 1 hour delay and then adjust your thermostat from heat to off.

I really hope that this makes sense as it's long winded.

[YB-Brighton]

This is great! I've just set it up to test... fingers crossed and will let you know what happens.

i was going through the Nest app, not the Home app.

[YB-Brighton]

It's working! ✨

Thank you SO much. I've spent about two weeks trying to figure this out and about six hours on the phone to various Google Nest Support people who just kept saying it couldn't be done. Nobody offered me this solution. They kept saying the only way to turn it off/on was manually.

Honestly, it would have cost me about £300 to get an engineer out to remove the Nest and replace it with a different programmable thermostat so I can't thank you enough.

i posted the same query over on Reddit, would you mind if I copy and attribute your solution on there as it will definitely help others?

[GBD]

You can go ahead and post the solution anywhere you want. I'm glad I could help you out.