A single-zone smart thermostat can either put the whole house’s heating on, or off. It can’t control individual rooms (well, not without automatic dampers – which are rarely fitted in residential homes). In my opinion, this is one of the many flaws of smart thermostats.
But what about smart radiator valves? Can these swoop in and save the day, giving smart, automatic and fine-grained control of your house’s heating after all?
Smart radiator valves can save you money, and are a good alternative to smart thermostats if you want room-by-room control of your house’s climate. However available products are currently limited, as are the number of integration options.
How do smart radiator valves work?
Before I talk smart radiator valves, it’s worth quickly talking about the different types of radiator valves. So a decade or so ago, most radiators just had the following:
This is a standard ‘T-joint’ for the pipe, meaning that any hot water being pumped from the boiler will pass around the radiator – meaning the radiator will always be on.
However as the world woke up to the eco-friendly shift, some countries started seeing more and more thermostatic radiator valves (TRVs) being installed:
These monitor a room’s temperature, and will only allow hot water into the radiator (i.e. only allow the radiator to ‘turn on’) if the ambient temperature is low enough.
Setting the TRV to “4” or “5 means that the radiator will turn on much more frequently than a setting of “1” or “2”.
Smart radiator valves take this a step further, however. Instead of just allowing a crude “1-5” numbering system for whether a radiator should come on (in relative terms), a smart valve can track the exact temperature of a room, and only hot water to pass into the radiator when a pre-defined temperature is hit.
And since they are smart, you can naturally use an app, automation rules or voice control to open/close the valve – thus allowing the room to be heated or cooled as required.
Smart valves are battery powered, so you’ll have to periodically change the battery otherwise they’ll just fallback to functioning as a standard radiator valve.
Can smart valves save you money?
In general, yes.
A smart radiator valve can save you money because it allows you to control your house’s temperature room-by-room. If you have a room that gets particular hot (for example), you can install a smart valve and make it so that that specific radiator comes on less.
Of course, you can also do this with a thermostatic radiator valve, but a smart valve will also allow you to control things remotely, along with including it in automation routines. For example, you might have a SmartThings routine that detects when you’re coming home, and then carries out a range of actions including opening certain smart radiator valves as required.
In some ways this makes sense. A smart thermostat will control your whole house’s heating, turning the heating up or down for all rooms in your house. If you don’t have TRVs (which most houses don’t), you might find that certain rooms get too hot – quite literally burning away money.
A smart valve can instead allow you to have fine-grained control of each room’s heating setup, potentially saving you much more money than with a smart thermostat.
Can you integrate smart valves with a smart thermostat?
This is where your heating system could truly become smart: a smart thermostat that truly learns your schedules and routines, combined with smart valves so that you can have room-by-room control of things. This is a smart heating system that would actually be useful (as you can tell, I’m not a fan of smart thermostats in a single zone!).
In this way, your smart thermostat could learn that people spend time in rooms A, B and C in the morning, then rooms D and E in the evening – and heat each room accordingly. A smart thermostat cannot do this without an expensive multi-zone setup.
So is this possible/feasible? Well… it depends on what smart thermostat you have.
The Nest Learning Thermostat has a support page on radiator valves, but it basically says to leave them at a standard/comfortable setting and then allow the Nest thermostat to control everything. In other words, it wouldn’t integrate with smart valves.
ecobee also doesn’t appear to support smart radiator valves, albeit they don’t explicitly mention this – they simply don’t talk about it. Plus their room sensors are meant to work in lieu of individual valves by sensing when people are in certain rooms.
As a result if you have a Nest or ecobee thermostat, your only real options are to integrate them with your smart home hub and then buy a compatible smart valve. I’ve seen some valves that have HomeKit support, meaning that you could setup some custom automation routines that combine your smart thermostat and smart radiator valves. Yes this isn’t direct integration, but it’s still a big step towards a truly smart (and automated) heating system.
The situation in the UK (and parts of Europe) is more promising, however. The Hive Active smart thermostat integrates with the Hive Smart Heating Thermostatic Radiator Valve, to deliver a seamless level of smart heating operability.
These Hive smart valves work without a smart thermostat, but if you have the Hive Active installed, you can also turn heating on in a single room (via the smart valve) without the rest of your house’s heating coming on. This is a pretty nice feature:
The Amazon reviews for the Hive valves are mixed, however, with 27% giving it a 1/5 rating and saying that they didn’t work properly. Installation issues seems to be the main issue (along with the odd software bug) – once they are installed and setup, however, many people say that they work really well alongside their Hive Active smart thermostat.
Can’t you just use TRVs (thermostatic radiator valves)?
This is the question I’ve been asking myself for a while, to be honest. My house only has TRVs and I certainly don’t feel the need to rush out and buy a bunch of smart radiator valves.
A TRV will have values 1-5 to indicate the temperatures they should come on at, along with 0 (and maybe a * option) to indicate it should stay off, or only come on occasionally. The numbers 1-5 vary depending on the make of TRV, but roughly speaking they mean:
- 1 – come on under 10-15°C
- 2 – come on under 15-17°C
- 3 – come on under 18-20°C (around 68°C)
- 4 – come on under 21-22°C (around 77°C)
- 5 – max (valve is always open)
This is what I have in my house and most of my rooms are set to “4”, with some set to “3” if a particular room tends to get a little too hot.
This works really well, and it’s a big step up compared to traditional radiator valves that are always open. The only things I lose with TRVs (compared to smart valves) are:
- The ability to smartly control the valves. But as we’ve seen, the current integration options are poor. If I could integrate smart valves into an ecobee thermostat, I think I’d run out and buy a full smart heating system. But right now that’s just not possible, so I don’t really see the benefit of having ‘smart’ radiator valves.
- More fine-grained control over when the valves open up. Right now I can just choose settings “1-5”, but this doesn’t allow me to say “This valve should be open under 18°C in the morning, and under 19°C in the evening”. This is something that I lose with my TRVs (compared to smart valves), but again – honestly – it’s not something I think would benefit me right now. Most of the rooms in my house are use evenly enough throughout the day, and most heat up (and cool down) consistently too – so I don’t need this level fine-grained control currently.
In short, if I didn’t have TRVs then I probably would go out and buy smart radiator valves. But since I already have thermostatic valves, I don’t see the benefit of upgrading to smart thermostatic valves.
Recommended smart radiator valves
Since most people around the world either have a Nest Learning Thermostat or an ecobee smart thermostat, but neither support smart radiator valves, it’s hard to recommend specific products to suit. Hence I’ll group my suggestions according to some example usecases:
You live in Europe and have the Hive Active thermostat
In this case, the Hive Smart Thermostatic Valves do make sense here. Yes, their reviews are mixed – so I’d suggest to read them, know what is annoying most people (it mainly seems to be a buggy install process) and see whether there’s been some recent Hive updates that make this process less buggy and annoying.
If this is the case, the £42.50-each Hive valves are more expensive than standard TRVs (costing under £8) but the fine-grained control they’ll provide you are probably worth it on balance.
You have a Nest or ecobee thermostat, and a smart hub
The choice here completely depends on your smart hub. The Eve Thermo, for example, supports HomeKit so if you’re using Apple’s smart home ecosystem, these Eve valves could make perfect sense (especially since both Nest and ecobee support HomeKit too).
Beyond this, if you have a SmartThings hub, you may consider either of the following smart radiator valves:
You have a Nest/ecobee thermostat, but no smart hub
This is trickier, because you probably won’t get great (or any) integration between your smart thermostat and your valves.
But in some ways this doesn’t matter – it just means that you have to manually manage some parts of your heating system. For example, you might know that the two back bedrooms get really hot as the day goes on, but your downstairs is cooler meaning that your smart thermostat comes on every day around 5-6pm.
In this case, you can use smart valves in just the two back bedrooms to turn off their radiators (or only have them come on at lower temperatures) at the same sort of time – e.g. 5pm. Then these rooms won’t overheat when your smart thermostat – reading the ambient temperature in your downstairs hallway or living room – kicks your heating system into action.
There’s quite a few smart valve choices in Europe’s Amazon stores, but much less in America’s Amazon store – so instead of trying to suggest a particular product which you might not be able to buy, I’d suggest to shop around retailers close to you and see what smart radiator valves they have for sale.