This guy killed entire Tado value proposition
I bought Tado and smart TRV's because I have a 3 floor corner house with 190m2 floor space and we live in first floor during the day and move to second floor during night to sleep (3rd floor is my office space).
I believe we have saved significantly last year by installing Tado smart TRV's and adjusting the room temperature seperately per each seperate hour and day. I thought having the functionality that Tado shuts down the boiler when we're not at home and starts up is a good idea.
However this guy https://www.youtube.com/watch?v=zpTVIeUh04E killed this entire use case and Tado business value. He's basically saying that if you heat individual rooms seperately you're making your boiler or heat pump to heat up the water temperature more to compansate the loss of radiator capacity (as the ones closed are lowering total radiator capacity) and more frequent on/off behavior is causing further inefficiency.
He says this is true for both CV boilers and heat pumps and we should never micro-zone our houses.
What do you think? Should I remove my Tado?
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i would ask what his credentials are first before making a judgment on his claims.
the fact that you have clearly saved money suggests that his claims don't match up with your real world results.
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It depends how you use the zones.
If you have zones that you switch off for periods of time then you will save some money. E.g not heating the office room at weekends or not heating bedrooms during the day. If you switch off one third of your radiators you're not going to save one third on energy, but you can save a bit. The insulation is on the outside and not on the interior walls, so heat will migrate between the rooms.
If you configure rooms to individually request heat then you are prioritising comfort over economy. A boiler often has a minimum heat output that will far exceed the output of one radiator. The constant on/off to heat a small amount of water can be avoided by grouping multiple rooms into a zone, or using the TRVs in Independent mode where they don't request heat. When one of your primary rooms requests heat then multiple radiators will start to heat.
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@GrayDav4276 out of interest, if you were starting now would you still choose Tado or might go you down a different route?
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i don't use the Tado app at all (apart from making sure the devices are added correctly) so all the fluff it tried to do is mostly ignored. everything i do is done via Homekit.
what would you choose now if you were starting again?
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Well, I think in my case it worked, but I have a gas boiler so frequent on/off and working with high heat probably not a big issue for gas boilers.
As far as I understand it becomes an issue with heat pumps, as their most efficient operating mode is low temperature flow and closing the radiators or rooms will require the flow temperature to be higher to compensate the loss of radiator capacity leading sub-optimal efficiency.
I really wonder what tado says about this as for most of the people controlling individual zones and closing the boiler when out of home is the reason to buy Tado.
As I said my experience is different but he has a very strong argument against Tado type of smart thermostates and smart TRV's.
Can anyone able to dispute what he's saying?
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However anyone calculates the theoretical efficiency and energy design of domestic home, it's like the an EPC: a calculated best guess for regulatory purposes. Nothing will match the 'real world' use and results. We use some rooms during the day (the west wing) and some rooms in the evening (the south wing). The bedrooms and bathrooms are warmed in late evening and early morning. Whilst there is obviously heat transfer between rooms through air conduction and convection, conduction through walls and ceilings, we can adjust the room temperatures as we need to be comfortable. We can also turn everything off when we leave home.
Four years of pre-Tado data gives a correlation of -0.8 for our heating/DHW energy use: annual kWh vs annual mean CET (outside temperature). 0.7 is a strong correlation. The nine-month real world energy bill check with Tado and CET is a saving of 24%-28%, that's about £500. Our original ROI estimate was 12 months. At present energy prices the real world ROI is 5 months. Comparing Tado energy savings in our 1960's home with a similar size new-build family home and UFH/Rads/ASHP, that's a lot better than their disaster-zone.
Would I do anything different? The answer is NO. We ignore the marketing spin as the Tado heating controls are effective and efficient in our two family homes with wet heating systems.
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@MED the guy is correct about ASHP efficiency, and it's because they generate heat entirely differently to a gas boiler. A good gas boiler might be 95% efficient, but you will never get the boiler to be 100% efficient. It's just not possible to burn 1 KW of gas and transfer all or more of the energy to the water.
An ASHP might be 300% efficient so you get much more heat than the amount of electricity used to power the ASHP. If you start zoning the radiators then the system will deviate from its design parameters. This will cause the efficiency to drop. So fewer rooms heated and you're using more electricity to do it.
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Zoning radiators, TRVs and UFH can make the water pressure sensors in an ASHP system have hissy fit. When the ASHP goes off-line, heating is ~% efficient (infinity or zero?) and very cold. I've learned a lot from the Hotblack Desiato ASHP Disaster-Area.
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I discussed with my ASHP installer about this, he generally disagrees with the guy simply because in my setup we have 3 floors and trying to heat the entire house with one thermostate measuring the heat in the downstairs is a sub-optimal solution as higher floors will be heated anyways and will be hotter.
You need to balance the TRV's so that those rooms are not that hot, but given the fact that I have a corner house depending on where the sun is shining and what hour some rooms can be hotter than the other ones.
He told me that actually Tado will not directly connect to the heatpump (I'm buying an LG Therma V Split type) so outdoor unit, indoor unit and hot water tank is seperate. Also this heatpump has a pump and Tado will talk to this pump to push the water or not. The heatpump has it's own reservoir of water and it will heat the water according to the flow temperature set for optimum climate outdoors.
So he told me that no need to replace Tado, in fact he loved the equipment and he would've suggested me to buy a similar one if I hadn't have one already.
Very confusing to hear very different opinions about something seems to be very simple :)
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I saw the video a few days ago. I've watched several of his videos and in general he comes across as knowledgeable and balanced in his views. He appears to be most interested in reducing carbon emissions and is an advocate of heat pumps as a solution, but only when installed correctly with a suitably designed system to meet the demands of each property. I think he has an interesting concept in "increasing the (total) size of your emitters by not zoning your rooms".
Speaking for myself, I've had Tado for one full year, with a condensing combi boiler and radiators sized for boilers back in the eighties with a non condensing boiler at the time. I have been targeting reduced flow temps and especially low return temps for my system, in order to maximise efficiency.
When I first installed Tado I did zone the rooms, with some turned off with closed doors and tweaking temperatures very specifically per room. I also had every SRT acting as a zone controller, able to demand heat and fire the boiler. This led to a really stupid pattern of boiler ignition, where as little as one needy radiator could cause the boiler to fire up, rapidly hit flow target temperature and force shutdown with a minimum output of 9 kW that cannot be dissipated through a single radiator. Then another radiator would do the same thing, and so on.
Since then I've modified my operation quite a bit. This is based partly on my own experience and learning, but influenced further by the video referenced above. I absolutely understand what he is saying.
As of today I have a single room - an "unused" bedroom - as the only zone controller. As it's October, and not yet too chilly, the heating is off overnight. More specifically, this one radiator is off overnight, so the boiler will not fire. All other rooms are set to 19C day and night. At 07:00 the heating comes on, with an 18C target for the spare bedroom. By this time some/many/all the other radiators are wide open and ready for some warmth. The boiler is range rated to its minimum output of 9 kW. Flow temp is set to 50C and pump speed is low.
Now my whole house is fed warmth at once. The boiler does not overheat. There is no short cycling. There are no cold spots or drafts. Internal doors can be left open without a thought. Currently my boiler doesn't even reach 50C. It's more like 40-42C maximum, before Tado turns it off. And then, with every radiator in the house warm at once, the temperature is quite stable. Also, the independent SRTs now act as temperature caps for the rooms instead of temperature targets. Thus no room gets overheated, and as each room hits target it then shuts down to leave more heat for the remaining rads until they are all satisfied, or close to it.
Now it's only been two days with this regime and it hasn't been that cold, but I get the strong impression that this is the way to go. I'd kind of been doing it anyway, but with the lounge as my zone controller instead of the spare bedroom. I think heating the "whole house" in this way, instead of individual rooms, is going to increase comfort and may even cost less than ever.
So, with all that said, is there any need for Tado or similar? Well, I'd say "yes" because it is still useful to be able to control temperatures accurately and to monitor room temperature performance. The SRTs are still performing a function, but controlling max temp rather than just temp.
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I think the heat geek guy elaborated more on this in a long blog post here: https://www.heatgeek.com/weather-compensation-or-load-compensation/
"TRV's can be used in conjunction with weather compensation, and efficiently too if used correctly. Set just above the target room temperature, this will prevent overheating in rooms that receive additional heat gain such as solar. Of course, this may not prevent the over-heat but it will stop putting energy in the room unnecessarily and lower the output of the appliance.
In general, it’s important to set TRV's above the required room temps as setting them too low will cause them to prematurely close and reduce the available emitter surface area, this will lead to requiring higher appliance temperatures to heat the property, or simply a cold property. It is for this reason, if you have unused bedrooms you must choose a temperature that isn't too low, a sensible 'set back' temperature is 2-3oc."
"If the upper half of the house is rarely used then zoning off at a lower temperature may be beneficial. However, if internal insulation is low then turning off or lowering the output of half the emitters in the property will cause the remaining half to run hotter to achieve the set room temperature as heat is lost into unheated rooms"
So really in my case having a house with 3 floors and rarely used rooms looks like the guy also agrees that zoning will make sense, but he suggests we don't shut down entirely but use a setback temperature 2-3 degrees lower than the active rooms' temperature level (which makes sense)
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Your set up is what I was considering switching to before I take the nuclear option and just put dumb TRVs back on... but I really do want to retain the ability to boost just a single room - does your set up allow that? I was under the impression that if you have multiple TRVs set up as a single 'room' like you do for your house, then turning up one rad would turn them all up, is that right?
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@Unkledunkle My TRVs are not set up as a single room. All but one are set as independent, meaning that I can set each room to any temperature I like, but none of them will receive any heat until my "master" TRV, my one and only zone controller, actually forces the boiler to fire.
If the room I want to boost is already my zone controller (or one of several zone controllers) then no messing required - just turn it up and the boiler will fire. All other rooms will continue to function with their own target temperatures as already set.
If I want to boost a single room that is not already a zone controller then I would need to adjust the temperature of that room and then, if necessary, also boost the temperature target of my "master" TRV in order to force the boiler to turn on. Alternatively I could add the room I want to boost back into the zone controller pool (no longer independent) and then I could boost that room and that room only.
Otherwise you could raise the temperature target of your boosted room and just let it take what it can get, heat wise, when your master TRV chooses to fire the boiler. It might not fully reach its temperature target, but it will at least grab all the heat it can whenever the boiler fires.
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It sounds like you've got:
- One room set up as a central thermostat control which works on a schedule for the whole house. You've set this up in an easy-to-heat room.
- All but that room acting as a if you'd installed a 'dumb' TRV that also has the ability to automatically schedule a maximum temperature at certain times and comes with a built-in temperature/humidity sensor and basic history information.
Is that a fair description? Or am I still not getting it (this is possible)?
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@Unkledunkle
Yep. That's correct. One master room controlling the boiler. Everything else as schedulable "dumb" TRVs.
This is exactly like the old fashioned system of having a (often) hall thermostat controlling the boiler and having dumb TRVs, albeit schedulable, throughout the rest of the house.
Except, my master thermostat is not in the hall or an easy to heat room. It is in a north facing bedroom that is last in the pipework to receive hot water and therefore more likely to cause the boiler to fire than not. I did have the lounge as my master room, but that is south facing, usually occupied and with the most electronic gadgetry on the go. Therefore it heats rather easily and stays hot quite well, so it would not need heat most of the time and the rest of the house wouldn't get heated as a result. The hall is similarly too easily heated, not least because it has my bypass radiator and always receives heat whenever the boiler is on.
The coldest rooms are actually the kitchen and bathroom, due to two external walls each and double air vents in the kitchen. However, due to the vents or heat from cooking, showers, cold from opening windows and venting steam etc. these rooms are not good candidates to set temperatures and control the boiler for the rest of the house.2 -
Understood. Thank you!
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Nope, not following this at all. I thought I had a similar set up to @eezytiger but now I’m totally confused with all this talk of zone controllers. My set up is as follows: I have a Worcester 38cdi erp combi boiler which can provide up to a max of 30Kw for the central heating. I have “range rated” this down to 50% to get closer to the 15kw max I think I would need if all the radiators in the house were on at once(probably nearer to 12Kw max demand). When I first installed Tado I replaced the Worcester RF11 reciever on the front of the boiler with the Tado wireless receiver, but then discovered that this wouldn’t modulate the boiler, so bought the Extension kit and fitted that instead. I have a total of 6 smart TRVs fitted in 5 rooms(2 in the lounge/dining room), and a wireless temperature sensor also in the lounge to control the 2 radiators. I also have a number of other radiators in hall and bathrooms that have either dumb TRVs or just manual valves on them. When I look at my Tado set up on the app, it’s the Extension Kit that is showing as the Zone Controller. Is this incorrect if I’m looking for a similar operation to that of @eezytiger ?
apologies for the length of this post!
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My understanding is that the main thermostat - your extension kit - which is connected to the boiler, must always operate as a zone controller. Otherwise it will not be able to turn the boiler on and off.
Any other SRTs or wireless temperature sensors can be set as additional zone controllers - i.e. they can command the boiler on if they wish - or as independent devices, which means they cannot force the boiler to turn on.
I have a wired smart thermostat in the hall, acting as my necessary zone controller to control the boiler, but at the chosen temperatures i have set for this device it is not likely to force the boiler to fire. I instead have my bathroom (it was the second bedroom, but I've changed my mind) as the real zone controller that actually decides when to turn the boiler on. The smart wired thermostat on the hall now acts simply as the physical connection to the boiler.0 -
Thank you for clarifying that @eezytiger
I think part of my problem with all this is how some of the terminology is being used.. as in Zone Controllers. It was my understanding that a zone referred to a heating circuit, so in my case i have 1 boiler and 1 heating circuit which has all my Tado devices fitted to it. In this thread though i think Zones and Rooms are being used interchangeably? is that the case? I also watched the Heat Geek video you refer to and had similar thoughts on what he was saying. Regarding my set up at the moment, as far as i am aware any of the SRTs in the 3 bedrooms AND/OR the wireless temp sensor in the lounge/diner can call for heat and fire up the boiler. If i understand your comments correctly you are saying that this is an inefficient way of heating the house? So how would I change my set up to be closer to your own?
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@eezytiger that’s not quite right. Zone controllers operate the boiler or zone valves in a multi zoned house. Only extension kits/wireless receivers or wired thermostats can be zone controllers. You set other devices to either be linked to the zone controllers or to be independent of them and not call for heat.
@Notascoobie you have a plumbed single heating zone house by the sound of it. In Tado speak rooms are equivalent to zones in the sense that smart trvs effectively create a multi zoned house. The most efficient way of heating your house is to avoid having too much heat differential between the different rooms unless they’re exceptionally well insulated.0 -
My house is 3 bed, 2 reception, kitchen, bathroom, hall, landing.
The hall wired smart thermostat has to be a zone controller in order to operate the boiler. All other SRTs are independent except the bathroom, which is really the room that decides when to turn the boiler on.
The bathroom is set to 19C from 07:00 to 09:00 to boost the whole house at the start of the day. Then from 09:00 to 22:00 it is set to 18C to keep things ticking along during waking hours. Overnight it is "set back" to 17C just to make sure the house doesn't cool excessively overnight.
Bedrooms and landing are set to 19C 24x7, but cannot force heating. They just grab heat when the boiler is turned on by the bathroom.
Downstairs is set to 20C from 07:00 to 22:00, then 19C overnight.
In this way there are many radiators open for heat whenever the bathroom needs heat and in this way I have several emitters/radiators working together to warm the whole house and keep my boiler efficient, with low flow and return temperatures.
Mostly during October the morning blast has been sufficient, with under 5 kWh burned for heating, and the house stays warm enough throughout the day and night until the next morning without using any more gas.
This morning the heating used 4.7 kWh to start the day. There has been no further gas use for heating today, nor will there be. As at 18:00 this evening, here's how my rooms are looking....
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@johnnyp78 , thank's for your input, you are correct, I have a plumbed single heating zone house. So basically all of my devices can request the boiler to fire up via the Extension Kit? As my wife and I are retired and at home most of the day, I was trying to work out the most economical way of running our heating. Currently 1 of the 3 bedrooms is not used and has a SRT fitted but the set temp is down at at 16c so at the moment it doesn't come on. The other 2 bedrooms are used and have SRTs fitted and set to 18.5c for an hour in the morning and an hour in the evening before bedtime. For the rest of the day I have them on a set back temp of 17c which at the moment they don't come on as temp stays above that level. This is all upstairs. I have a different regime for the Lounge/diner and the study which are downstairs and used for most of the day. Heating is scheduled to come on at 0800hrs at 18.5c till 12noon. Noon till 2pm 19c, 2pm till 4pm 19.5c, 4pm till 6pm 20c and 6pm till 1030pm 20.5c. This is working well at the moment as the upstairs radiators are not kicking in as the temp is still above 17c in those rooms, partially due to an over flow radiator in the upstairs hall which tends to heat the bedrooms if the doors are left open. My concern is that when the colder weather arrives(we are in Scotland) the temp in those upstairs rooms is going to drop and the SRTs will be firing up the boiler a lot more to maintain the minimum temp of 17c. So my question is, at that point would it be better from a financial standpoint to adopt @eezytiger approach of keeping the whole house at a uniform temperature, OR keeping things as they are and having the bedroom SRTs calling for heat whenever the temp drops to below 17c, OR putting the bedroom SRTs to a much lower setting where they don't demand heat at all through the day, but have a much harder job to do heating the bedrooms when they are scheduled to come on in the evening? Not asking for much, am I?🙄
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@eezytiger You Said "This morning the heating used 4.7 kWh to start the day. There has been no further gas use for heating today, nor will there be. As at 18:00 this evening, here's how my rooms are looking...."
Blimey, that's good! According to my smart meter so far today I've used 21.95Kw/hrs!
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@Notascoobie Haha! I've actually used 6 kWh of gas in total today, but that includes 1 kWh for a shower and a bit more for cooking.
Here's my October gas use so far this year compared to last. The 30 kWh day was when we had a chilly guest and had to turn the heating up a few degrees. Otherwise, happy days.
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If you want to maintain that temperature I don’t see any way you can avoid having the heating on for longer when it gets colder. If you had a weather compensation system it would modulate the boiler’s output higher, which would have the same result. I think the least efficient way is to force cold rooms to come up to the target temperature, which also means the radiators in hot rooms will be working harder to heat that room as the heat leaches into the cold rooms.
As long as there’s only a couple of degrees’ difference between the rooms that should be relatively efficient, or you can go @eezytiger ’s route of not allowing rooms to call for heat and (possibly) have a bigger temperature difference (depending on your house insulation level). It all depends what you consider comfortable versus what you’re willing to spend.0
