thermostat

No more Google Nest themostats in Europe

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A photo of our Nest thermostat with the heating set to 19 C

I’m a little bit late on this, as the news came out a couple of weeks ago. Google is dropping support for its oldest Nest thermostats, and will stop selling the newest models in Europe, once its stock is depleted.

This is relevant for me as we had a Nest thermostat installed nine years ago. Now, as far as I can tell, it’s not one of the models that’s being dropped. However, Google and Nest haven’t made it massively straightforward to check.

There is a ‘How to tell which Nest thermostat you have’ help page, but the information is different depending on where you are. Compare and contrast the UK and US versions:

The reason for the discrepancy, and the given reason for withdrawing the product altogether from Europe, is that:

“Heating systems in Europe are unique and have a variety of hardware and software requirements that make it challenging to build for the diverse set of homes”

However, when I’ve looked, I appear to have a third generation thermostat, but a second generation heat link. The heat link is the rounded-square white box that is wired up to your boiler. I’m hopeful, therefore, that I do indeed have a third generation thermostat. I haven’t had an email about it yet, that’s for sure.

If it does transpire that I have an older thermostat, then it’ll only work locally. That means that it’ll still control the boiler using the schedule set up on it, but users won’t be able to use either the Nest or Google Home apps to control their thermostat. And features like Home/Away assist will also stop working. In tandem with this, the old Nest app is being retired altogether, with all functionality moved to the Google Home app.

I assume that this will also apply to anything that uses Google’s APIs, so users won’t be able to use Home Assistant as a workaround, for example. The change takes place on the 25th October this year.

Compensation

As well as notifying affected users by email, Google is offering money off its newer thermostats for those who want to upgrade and keep their smart features. Of course, as Google is withdrawing its thermostats from Europe, European users are instead offered 50% off a smart thermostat from Tado, which costs €199 normally. The same kit is currently £149 from Amazon (sponsored link) but I’m guessing the discount code will only work for direct orders. Tado smart thermostats will work with Google Home, and with Home Assistant, but they’re still cloud-based like Nest’s thermostats are.

And this is the concern I have. I’ve trusted Nest, and later Google, to provide a cloud service, which they’re now taking away for some users. Whilst this (probably) doesn’t affect me now, further changes in a couple of years could mean that my thermostat becomes unsupported as well. And if Tado decides to do the same with their thermostats, users could be inconvenienced twice.

Google has been killing off a number of its smart devices recently. In March, the Google Nest Protect was discontinued (I also have one of those), and I’ve recently blogged about the removal of Google Assistant from Fitbit devices. And it’s not like Google hasn’t got form when it comes to killing off products. Killed by Google lists almost 300, and it actually hasn’t been updated in a few months. Indeed, I’m still bitter that Google Reader was killed off 12 years ago.

Finding alternatives

I think what’s worse about Google killing off its older thermostats is that they’re not so easy to replace. A thermostat needs to be professionally installed. It’s not like a phone, or a smoke alarm, or a smart speaker, where the old one can simply be unplugged and replaced. And they’re not cheap – I paid £250 for my Nest thermostat back in 2016. Even with the discounts, you would still have to find someone to install it for you.

In time, we’ll be replacing our gas boiler with a heat pump, and when that happens, I’ll look to replace to Nest thermostat with something else. It won’t be Tado, as outlined above. At the moment, I’m leaning towards Drayton Wiser. It works with both gas boilers and heat pumps, and supports smart thermostatic radiator valves. It can also work locally – indeed, the Home Assistant integration (installable via HACS) doesn’t require the cloud at all. Others who I’ve talked to in smart home communities recommend it, but I haven’t experienced it myself.

I suppose, knowing Google’s history, that I should have been more wary about relying on Google hardware for my heating.

A temperature-controlled fan using Generic Thermostat in Home Assistant

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A screenshot of the description of the generic thermostat integration in Home Assistant

So earlier this month, in my review of the ThermoPro Bluetooth Thermometer, I mentioned some ‘additional functionality’ in Home Assistant that I would write about. Well, later is now, and I’m going to talk about how I have a temperature-controlled fan in our bedroom, powered by Home Assistant and its Generic Thermostat integration.

Generic Thermostat is one of the older Home Assistant integrations, having been around for several years. It allows you to take any temperature sensor, and any smart switch, and automatically turn the switch on and off in response to temperature fluctuations. In essence, Home Assistant itself provides the thermostat functionality.

The switch should power something that can either heat up or cool down a space – for example, a plug-in heater, or an air-conditioning unit. In my case, I’ve hooked it up to a standard pedestal fan, and used a smart socket to turn the fan on or off at the plug.

Enabling the integration

Note: within days of publishing this blog post, Home Assistant 2024.7.1 was released, which allows you to configure the Generic Thermostat through the Lovelace UI, so you don’t need to add the YAML code anymore.

I mentioned that it’s an old integration, and sadly it’s not one that has been updated much since it was implemented. This means that you can’t add it using the Home Assistant interface (Lovelace), and instead you’ll need to add it to your configuration.yaml file.

Here’s mine:

# Generic thermostat
climate:
  - platform: generic_thermostat
    name: Bedroom thermostat
    heater: switch.bedroom_fan_socket
    target_sensor: sensor.tp357s_55ab_temperature
    min_temp: 15
    max_temp: 30
    ac_mode: true
    target_temp: 19
    cold_tolerance: 0.5
    hot_tolerance: 0.5
    min_cycle_duration:
      minutes: 20
    away_temp: 19
    precision: 0.1

Here’s what each variable refers to:

  • Platform specifies the integration, and the Name is the friendly name of the device.
  • Heater is the name of the entity that controls the smart socket that the fan is attached to.
  • Target_sensor is the name of the thermostat entity that provides the temperature.
  • Min_temp and Max_temp set the minimum and maximum temperatures that you’ll see on the Climate card in Lovelace – I’ve set these to 15°C and 30°C respectively.
  • AC_mode is set to ‘true’ because we’re using a device that’s supposed to cool down the room. If this were a heater, I would leave this line out.
  • Target_temp is the temperature that I want the thermostat to achieve, which is 19°C.
  • Cold_tolerance and Hot_tolerance mean that Home Assistant will only turn on the fan when the room reaches 19.5°C, and will only turn it off when it reaches 18.5°C.
  • Min_cycle_duration means that if Home Assistant turns the fan on, it should stay on for at least 20 minutes, and vice-versa, so it’s not constantly cycling on and off.
  • Precision is how much precision I want when setting the temperature; at 0.1, this means I can set it to 1/10th a degree.

Once you’ve added or amended the settings for your thermostat, you’ll need restart Home Assistant.

How it works in practice

So, once set up, if the temperature in our bedroom reaches 19.5°C, the fan will come on. It’ll then stay on until the room reaches 18.5°C, or 20 minutes, whichever happens first.

You can also control the thermostat like you would with, say, a Nest thermostat through Home Assistant. It will create an entity which you can add a card for on your dashboard. So, although you may have set a target temperature in the initial configuration, you can change this without editing your configuration file. However, if you re-start Home Assistant, it may forget this.

If you also use Google Assistant or Alexa, then you can also make them see and interact with your generic thermostat, if you have integrated these with Home Assistant.

Whilst I use a fan and a smart switch, if you have an air conditioning unit with an RF control, you could use an RF bridge to allow General Thermostat to control it.

Fans vs air conditioning

If you do use a fan with Generic Thermostat, you’ll notice that your fan may stay on for a long time. That’s because fans don’t actually cool the air; they move air around which helps sweat evaporate more quickly. That makes you cooler, but not the air around you. It’s a bit like a hot day at the seaside, where the breeze takes the edge off the heat.

Air conditioning systems actually cool the air down, but are much more expensive and need an outlet for the hot air to be pumped out. Most British homes don’t have air conditioning, including ours – most of the year, it’s too cold, and our houses are designed to retain heat.

Nesting

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A photo of our Nest thermostat with the heating set to 19 C

Along with our new boiler, we also got a new thermostat – a Nest Learning Thermostat. I’d actually bought it in January, in the hope that it could be fitted to our existing 1970s central heating system. With both Christine and I being on maternity and paternity leave respectively, we were at home most of the day and so the heating was on almost constantly – I hoped that a better thermostat would cut the amount of energy required. Alas, the fitter who came to install it told us that our system was too old – he could fit it, but it would only power either the hot water or the heating, and not both at the same time.

Now that we have a more modern boiler, we could also make use of the new thermostat.

The previous thermostat also dated from the 1970s and was a basic model that, theoretically, would heat the house until it reached the set temperature and stop. But I’m convinced that it didn’t do the latter – the heating would still be on even when it was utterly roasting. With such an old system, the fault could have been in any one of several places. Either way, it’s not an issue now.

Whereas the old thermostat was upstairs, we’ve fitted the Nest in the dining room. You can install it using the standard thermostat cables to your boiler, or there’s a micro-USB socket and an AC adaptor included. We decided to go for the latter, in case we want to move it somewhere else. It’s quite easy to fit to the wall and the backplate even includes a spirit level to help you align it correctly.

The Nest offers several useful features:

  • It learns how long your heating system takes to warm up. So if you want the house to be warm by 7:30am, you tell it that, rather than telling it to come on at 7am in the hope that your house will be warm enough by then.
  • You can tell the thermostat that you are away, allowing it to maintain the house at a cooler temperature, thus saving energy.
  • Your thermostat can be managed using official apps for smartphones or tablets, or on the web.
  • It has a motion detector, so the display turns off when no-one is about. It can also turn your heating down if it detects no motion in the house for some time.
  • Integration with IFTTT and other smart home technologies.

Whilst it’s been a warm couple of weeks, thanks to the Nest our heating has only needed to be on for an average of 30 minutes per day. I’m hoping that it will save on our energy bills – my mother-in-law has one, and she credits hers for halving her gas bill.