Smart TRV's - are they worth it to add to a tado smart thermostat and boiler control?

Here’s a Heat Geek article that I’ve just found.

Heres their YouTube video on the subject

Tado just did a BAAAAD thing

They decided to do some market testing and a few days ago (19th February 2025) people logging into the App got a message to say that they would now have to pay £1 a month to access their heating controls. Well, after you had gone though the (as it turned out fake) page entering your card details they suddenly announced: Just testing! It's still free. Which has spooked their customers.

Have a read through this which gives a much more detailed explanation from Louis Rossmann who I follow on YouTube.

https://wiki.rossmanngroup.com/wiki/User_testing_for_mandatory_paid_subscription_into_Tado_Smart_Thermostat_app

I very strongly recommend that you read down to the bottom of the document as to the possible implications of what they have done and the blurred lines between what you might think is your ownership of these devices and a rental agreement.

I've just done an experiment with my Tado smart plugs to see if there is any local control with all the devices and my smart phone on the same WiFi router. Both are still connected to the router.

The answer is no. If you lose your internet connection, not only do you lose any remote control you lose any local control. This means that all control passes through Tado servers all of the time. Unplugging the phone line from the router sends all your devices offline within a minute or two even though the devices are still showing as connected to the WiFi. If you switch off the router the devices show as not being connected to the WiFi (as you might expect).

I'm definitely having second thoughts about expanding my Tado set up although I have just discovered that you can have an internet free system using a Home Hub but even that isn't straightforward.

If I were to consider home automation now then I would be looking for one with native local control without its functionality being dependent on being connected to the cloud except for remote control funtions / operation.

I definitely won’t be buying TADO then as I’m not prepared to be held hostage to a subscription service.  Hopefully I’ll find a similar system where I can use something cheap like home assistant green and retain all of my data and investments.

It's funny but it's events like these that make you realise how little control you have of internet connected devices when it's supposed to give you more control.

I have an EV and I went through a similar experience with trying to sort out a charge point which I thought would be a trivial exercise compared to choosing an EV. Not so. There are very similar issues over control and in the end I built my own dumb charge point as I'm able to do that. It's simple, reliable, cheap, repairable, with the right tariff it saves a lot of money and I have full control over it. It's unfortunate that we have a tendency to overcomplicate solutions.

I hope you find a better solution

Peter

I was looking for local control devices and came across this site which may be useful for those going down the home automation route but wanted local control. It's dated this year so it has relevant information.

https://hometechhacker.com/5-local-control-alternatives-to-popular-smart-home-products/

Peter

Thanks for the link which I’ll study later.

I suspect that most of the smart thermostats on the UK consumer market use internet data for outside temperature.   Here’s a DIY system listed on the BBC that I saw a while ago, costing only £15, I suspect using a raspberry pi pico or similar.
https://www.bbc.co.uk/news/business-62900202

Unfortunately, after checking with Bosch, it looks as if my older condensing combi isn’t compatible with weather compensation anyway.
 

But if you manipulate the thermostat so that it looks like weather compensation then it is weather compensation. I'll give you an example.

I've got a new Vaillant gas boiler with a remote thermostat RT (that transmits and receives both ways) which has a temperature readout on the front. But, the temperature readout on the RT is a lie, an untruth a fabrication. How do it know this? I have an accurate digital thermometer DT next to it and most of the time they read the same until the boiler starts the pump to sample the radiator return water temperature which happens when the room temperature edges down a bit. If it's close to the set point the boiler instructs the RT to suddenly display a lower temperature, significantly lower than the DT next to it. The RT tells the boiler to come on for a short while and after a while it then instructs the RT to display the same temperature as my DT and to switch the boiler off.

The boiler is manipulating the RT display so you can't use it as an actual thermometer. In old school terms it's removing the hysteresis inherent in heating systems by pre-empting a temperature undershoot but manipulates the display to ‘justify’ its actions which is quite unnecessary unless it needs the ‘lower temperature’ to cause the RT to command the boiler on. I'm not complaining, it works extremely well, but I hate displays that lie because ultimately you can't trust what they are saying.

Back to the weather compensation. If you are monitoring the outside conditions, presumably you could add in solar gain (heating) and high winds (cooling) for your particular house, then you could manipulate the temperature set point of your thermostat to cause the boiler to react accordingly. Voilà

But weather compensation on my heat pump alters the flow temperature, it doesn’t switch it on and off…. 

​@juliamc Good point. I've just had a look and it's the same for gas boilers and heat pumps. My Vaillant modulates the water temperature so maybe it's a halfway house mechanism to achieve its high efficiency because that is what weather compensation is about. Probably wouldn't work for an older condensing boiler so well.