Tado smart thermostat without central thermostat/controller

RD_17

I was thinking of installing the Tado smart radiator thermostat system - this comprises only smart thermostatic radiator valves with a central internet bridge connected to my router that communicates with the thermostats. There is no "main" room thermostat or contoller attached to the boiler. I have a combi boiler that turns fires when requests are made from my current TRVs.

Is there any disadvantage to not having a controller attached to the boiler and main room thermostat? It seems much cheaper without this - but do I lose much? The only thing I can think of is that a room thermostat is probably better at measuring the temperature as it can be place centrally (but only for one room). I lose the ability for the system to turn on/off the boiler but I don't see that as a particular issue as the requests for heating from the TRVs effectively do that already.

matelodave

What sort of TRVs have you got which request heat from the boiler - thats a unusual arrangement unless the they just open and the boiler tries to keep the hot all the time (which is a pretty inefficient arrangement)

Most systems use a central thermostat to actually fire the boiler and shut it down again, rather than relying on the boiler stat to keep the system hot all the time.

Dunno about the TADO system but most systems of that ilk require a central controller to communicate with the separate stats/valves/boiler/etc so they can be remotely operated. I guess that an individual TADO trv would just sit there and possibly do it's own thing but I doubt that you could communicate with it without the central controller. Unless it's controlling the boiler as well there's not really a lot of point in having one.

As far as I can see you need an internet bridge to be able to remotely control and monitor the TRV's so unless you buy into the system you are not really any better off than with a programmable thermostat head - these are cheaper and use bluetooth so you could control them in the house but not remotely. https://www.amazon.co.uk/Bluetooth-Programmable-Thermostatic-Radiator-Thermostat/dp/B07F45F3MN

You'd need to study the data sheets and installation/commissioning info to establish exactly how it operates

ianto11

If you mean smart TRVs without the smart thermostat I'm not sure how this would work ? and I don't see the how it would be different over your current TRV,s ?.
Currently your TRV opens, boiler temp drops boiler fires....Tado TRV, would do exactly same ..no ?

https://support.tado.com/hc/en-gb/articles/115000533286-Do-I-need-Smart-Radiator-Thermostats-in-the-room-in-which-I-already-have-a-Smart-Thermostat-installed-

Above article seems to indicate the smart TRV's call for heat through the smart thermostat ?

You have no timer controller for your boiler at the mo ? does that mean your heating is on 24/7 or do you switch it on and off as required ?
I have the smart themostat and extension kit, no Tado TRv's and this allows for an extremely customisable system

You'd be better to contact Tado whether this actually possible, and @ £50+ a pop, hardly a cheap alternative

RD_17

Hi! Thanks for the response. I'll try to clarify what I mean.

matelodave wrote: »

What sort of TRVs have you got which request heat from the boiler - thats a unusual arrangement unless the they just open and the boiler tries to keep the hot all the time (which is a pretty inefficient arrangement)

Just standard TRVs - I thought this was how they worked? For example, I have a TRV set to a certain level and when the temperature drops below the TRV allows water into the radiator, and the boiler may then fire to replace the lost heat. The little green LED lights up on the boiler, which the instructions describe as meaning the boiler is "responding to a hot water/heating request".

matelodave wrote: »

Most systems use a central thermostat to actually fire the boiler and shut it down again, rather than relying on the boiler stat to keep the system hot all the time.

I think this is the core point I don't understand. In a scenario without the central thermostat, the boiler will fire whenever the temperature in one room falls below a set threshold. This is the same as with the central thermostat and smart radiator valves. When nothing is requesting heat then there is no energy cost. What's the difference?

matelodave wrote: »

Dunno about the TADO system but most systems of that ilk require a central controller to communicate with the separate stats/valves/boiler/etc so they can be remotely operated. I guess that an individual TADO trv would just sit there and possibly do it's own thing but I doubt that you could communicate with it without the central controller. Unless it's controlling the boiler as well there's not really a lot of point in having one.

There is a Tado setup that does not require the central controller, and seems to allow full functionally through a smart phone connecting to the internet bridge. I could not post a link as a new user, but if you Google "How does tado control radiator heating systems without a central thermostat?" then the first result should be the system I am interested in. I'm trying to understand what I lose with this system compared to a more conventional one.

RD_17

ianto11 wrote: »

If you mean smart TRVs without the smart thermostat I'm not sure how this would work ? and I don't see the how it would be different over your current TRV,s ?.
Currently your TRV opens, boiler temp drops boiler fires....Tado TRV, would do exactly same ..no ?

Above article seems to indicate the smart TRV's call for heat through the smart thermostat ?

You have no timer controller for your boiler at the mo ? does that mean your heating is on 24/7 or do you switch it on and off as required ?
I have the smart themostat and extension kit, no Tado TRv's and this allows for an extremely customisable system

You'd be better to contact Tado whether this actually possible, and @ £50+ a pop, hardly a cheap alternative

Hi! If you Google "How does tado control radiator heating systems without a central thermostat?" then you will see the setup I'm talking about. The advantage for me over standard TRVs would be able to set a schedule for each room e.g. warm up the bedroom and living room only from 6:30am, warm up kids room half an hour before their bedtime etc. Plus the Tado ability to use geolocation to detect when nobody is present in the home and reduce room temperatures accordingly.

Currently we have no timer or thermostat at all for the boiler - only moved in at the end of last year and just getting round to sorting this. This means it is quite expensive to install these components and given that I would like individual room control I am trying to figure out if I need the boiler controller and thermostat at all!

My costing is around £30 per radiator thermostat - I am a cheap person so am buying Tado V3 radiator "starter kits" that contains two thermostats and an internet bridge for about £90-£100, then selling the spare bridges on Ebay for about £30-£35 each. The total cost will be about £270-£300 for the eight radiators in my house this way. I estimate the cost with a controller, central thermostat and installation would be at least double this. However, I can't find anyone who has actually gone down the path I am thinking of, so I am asking here what the flaws are with my idea.

ianto11

Do the smart thermostats have a manual override on them, as the only potential issue I would see is that the scheduling part of the setup is stored on Tado server..not locally ?

My extension kit has a manual override button to switch on the heating if I have no internet, or the Tado servers are down

RD_17

ianto11 wrote: »

Do the smart thermostats have a manual override on them, as the only potential issue I would see is that the scheduling part of the setup is stored on Tado server..not locally ?

My extension kit has a manual override button to switch on the heating if I have no internet, or the Tado servers are down

I believe the radiator thermostats can be adjusted manually. Good point about where the scheduling is stored...

matelodave

If you don't have a thermostat then I'd guess the boiler is trying to keep the heating water hot all the time and could be running the pump to circulate water through a bypass valve.

When a TRV opens the hot water is then allowed to flow through the rad, the water temperature drops and the boiler tries to replenish the heat.

It's not the most efficient way to run the boiler - ideally the room stat (or the TADO extension) would operate as the boiler interlock and then only run the boiler when the system calls for heat.

I think the scheduling is stored on the TADO servers rather than in the unit or on your smart phone - dunno you'd have to check with TADO

ianto11

I think this is the core point I don't understand. In a scenario without the central thermostat, the boiler will fire whenever the temperature in one room falls below a set threshold. This is the same as with the central thermostat and smart radiator valves. When nothing is requesting heat then there is no energy cost. What's the difference?

If your boiler is on there will be heat loss locally so boiler will cycle regardless of demand for heat, central thermostat negates that, once up to temp, boiler is off completely until temp drops

RD_17

matelodave wrote: »

If you don't have a thermostat then I'd guess the boiler is trying to keep the heating water hot all the time and could be running the pump to circulate water through a bypass valve.

When a TRV opens the hot water is then allowed to flow through the rad, the water temperature drops and the boiler tries to replenish the heat.

It's not the most efficient way to run the boiler - ideally the room stat (or the TADO extension) would operate as the boiler interlock and then only run the boiler when the system calls for heat.

I think the scheduling is stored on the TADO servers rather than in the unit or on your smart phone - dunno you'd have to check with TADO

Ah yes, I see what you (and Ianto11) mean. We would need to turn off the boiler manually when we leave and overnight when going to bed, as we currently do. To have the heating come on prior to getting out of bed would require the system to be losing some heat in the pipes overnight while we sleep. Reading up a little more, I think the Tado extension is what we would need, then wire this up to the boiler to allow the Tado software to turn of the boiler entirely when not needed.

I think I understand the situation. Previously I did not realise the system would still be pumping hot water even if no radiators had valves open. Not a huge loss I guess assuming the pipes are insulated properly, but probably worth the £60 or so for the extension (and figuring out how to install it to avoid installation costs!!). I don't think I'm going to bother with the central thermostat though.

Thanks all.

matelodave

It might be worth having a word with TADO to make sure that the TRVs will actually work with the extension so that each valve can turn the boiler on and off when they call for heat.
It would seem reasonable that it should but its worth checking before lashing out loadsa money