Smart heating systems, such as Hive and Nest, seem to be all the rage at the moment. While they can help save money and make controlling your heating easier, they're not as smart as the Honeywell Evohome. While most smart heating systems replace the thermostat and timer controls in your home, the Evohome is a true room-by-room heating system. It's a subtle, but important difference.
With a thermostat-based heating system, you're controlling when and how your entire home reaches a set temperature; with Evohome you control each room individually. For example, you can have your bedroom and bathroom come on in the morning, your lounge at lunchtime and your kitchen in the evening, all set to their own ideal temperature. It means you only heat the parts of your house that you're using, rather the entire thing.
Of course, you can control everything from your smartphone over the internet, as well as using the dedicated touchscreen controller and individual controls in-house, making this a smart system in more than one way.
EVOHOME INSTALLATION
Honeywell recommends that the Evohome is installed by a professional, although the enthusiastic amateur may be able to do it themselves, depending on their current plumbing.
Evohome comes as a set of components that are tied together wirelessly to create your heating system. Some are required, but some are optional, letting you expand and improve the system over time. First, there's the wireless relay that is powered by and connected to your boiler. This replaces the thermostat and heating controls of a regular heating system. A second relay is required specifically for hot water if you have a timed system; combi-boilers only require the heating version.
Next, you've got the Controller, which wirelessly communicates with the Radiator Controllers and the boiler relay. This touchscreen device can be wall mounted, although it ships with a desk stand that plugs into a mains socket. This is the component that replaces your standard timer controls, although it's far more advanced. The Controller and Relay are the only two components that are required, with the former also acting as a room thermostat. In this simplistic mode, you effectively replace your current system with smarter, more controllable heating controls. It also gives you a cheaper way into Evohome, starting with the basic system and giving you the option to upgrade at a later date.
Realistically, you want to start with a system smarter than the basic one offers, which means buying some Radiator Controllers, too. These attach to standard Thermostatic Radiator Valves (TRVs) and let each radiator and room be controlled individually, measuring the local temperature. It makes a lot of sense to go for the whole hog and kit out every room with these in one go, otherwise the system won't be as efficient or clever as you'd want it to be. For example, if you don't have a Radiator Controller in, say the bathroom, it would mean the bathroom radiator would heat up when any other room triggered the boiler.
Finally, there's the optional Gateway, which plugs into your router and lets you control everything via the smartphone apps (Android and iOS). While not essential, we think it's a key part of the system that every prospective Evohome owner should opt for.
With everything connected, all of the devices need to be bound to the Controller, putting each Radiator Controller into a zone. Up to 12 zones can be defined and how you do it will depend on the size of your house. A zone can be a room with a single radiator, a room with multiple radiators or multiple rooms joined together. Unless you've got a massive house, room-by-room control is probably the way to go.
HONEYWELL EVOHOME CONFIGURATION
Once everything's set up the timing schedule has to be configured from the Controller. It takes a little while to work out what to do, as Evohome is a little different. With a traditional heating system you set one temperature for the entire house and then choose at which times you want the heating on and off. With Evohome the heating is technically always on, but you decide what temperature you want when for each zone. When any of the zones drops beneath the temperature it's currently set to, it signals the boiler to fire up, warming up that single radiator.
Each zone can have up to six switch points, each with their own time period and their own temperature. For example, you may set a bedroom to be 12C over night, warming to 18C for the morning, before falling to 9C when nobody is in, coming back to 18C ready for the night.
Each day can be different, letting you set your schedule based on exactly when you and your family use each room. While you can tweak each zone manually, there's also a brilliant wizard that asks you simple questions about when you use each room to set things automatically. Even with the wizard, it takes a good week or two to get everything set correctly. We found that we had some rooms to hot and some too cold, as we'd based our initial settings on the old house thermostat.
While the schedules you set will give you a warm house for the main part, flexibility is key and you can override any setting at any time, either to cool a room down or heat it up. This control can be done via the Radiator Controller, Controller or smartphone apps, which we'll look at next.
HONEYWELL EVOHOME RADIATOR CONTROLLER
The Radiator Controller is one of the most important parts of the system. These battery powered radiator valves are what control each zone's temperature and react to the scheduled commands.
More than that, Radiator Controllers are their own smart devices, reacting to user control and its own ambient sensors to give finer control over the heating. For starters, each Radiator Controller has a window sensor built in, which detects when you've opened a window. Assuming that this means you want to cool down a room, the valve shuts the radiator off for a set period of time (30 minutes is the default). For better accuracy, an optional physical window sensor can also be attached.
As well as reacting, the Radiator Controllers let you interact with them. Twist the dial on the top and you can wind the temperature of a room up or down, with the set temperature displayed on the clear, backlit screen. It's a brilliant and simple method of controlling a room's temperature without having to reach for a smartphone or the Controller. Any changes made this way are kept until the next scheduled temperature switch point.
For convenience the screen can flip out of its housing. Honeywell even provides a plastic wedge to keep the screen out if you prefer it that way. A settings menu also lets you choose some options. They include changing the default view, so the Radiator Controller displays the current temperature, rather than the set temperature.
Depending on the Radiator Controller's position, you may have to use an external wireless sensor instead. For example, if you've got a radiator behind a sofa, it may get too hot, turning off the radiator before the room has had time to heat up. Fortunately, Honeywell makes it easy to use the replacement wireless thermostat instead. All you need to do is bind the new wireless thermostat, complete with its own temperature controls to the Radiator Controller and the job's done. Wireless thermostats come with a table mount, but you can also wall-mount them for convenience.
The Radiator Controller uses a motorised valve. It takes a little while to get used to and the electric whirring can penetrate a quiet room, such as a bedroom. We recommend making sure that each valve is screwed firmly into position, as a slightly loose one in our bedroom made a little too much noise. However, as the system adjusts to your radiators over time, the Radiator Controller gets quieter, plus you get used to it.
Two AA batteries should last around two years and replacing them is a simple matter of flicking the unlock switch on the bottom, picking the Radiator Controller up and switching the cells from underneath.
HONEYWELL EVOHOME CONTROLLER
While the Radiator Controllers give you quick control, it's the Controller that you'll probably use the most, as it gives you more and finer control over your home. The touchscreen controller can be carried around and used where you want it, but it only lasts a couple of hours away from its dock. Really, we would have expected a lot more and a night's worth of battery would have been ideal.
The Controller lets you override a zone's temperature. By default, the override lasts until the next scheduled temperature change, but you can set an end-time or make the change permanent. These overrides can be disabled quickly with a single tap at any point.
Through the Controller, you've also got access to Quick Actions. These let you override the schedule with a different action and include Economy, which reduces the set temperature in every room by 3C; Away, which changes every room to be 15C all day; Day off, which uses Saturday's schedule; and Heating off, which turns off the heating completely. All of these modes, bar Heating off, can be tweaked to work the way you want. Then, you've got a single custom mode, which applies a different schedule to a set of zones: for example, your may have a guest schedule that ramps up the temperature for a spare bedroom.
All of the Quick Actions can be enabled permanently, until you disable them, or with a long-press, set for a defined period of time. Only one Quick Action can be enabled at a time.
The Controller also has a set of Advanced options. These include setting how many times in an hour the boiler can be turned on and off, and the cycle time: the boiler's manual should tell you these things, but it's another reason why a professional may be better off fitting the system.
More interesting are the optimisation modes you can apply. No Optimisation means the system works as you'd expect with the heating turning on when you schedule an increase in temperature. Optimum Start learns how long each room takes to warm up, turning the heating on to have the room at the set temperature at the set time; Optimum Stop will turn the heating off up to an hour earlier, if a zone is within 0.5C of its set temperature. For most people, Optimum Start is the best option.
HONEYWELL EVOHOME SMARTPHONE APPS
The third way to interact with your heating is via the iPhone and Android apps. The clear interface is easy to use, telling you the current temperature and current set temperature of each room. It's brilliant that you can turn on (or off) your heating from anywhere, particularly if you're heading home early.
Since the system was launched, Honeywell has upgraded and revamped the app, fixing our initial criticisms of it. When launched, the app would let you set a temperature, but you could only set it as permanent, or choose a time for the override to last until, as it didn't know when the switch points where. With the update that all changes. Now, when you set an override via the app, the default is to keep the new temperature until the next scheduled switch point, although you can still make the change permanent.
You can now also use the app to make changes to your schedule, which you couldn't do before. Using the app isn't quite as good as using the Controller, though, as you can't copy a schedule from one day to another, or to another room. For wider-reaching changes, then, you still need to revert back to the Controller.
While you can use the Quick Actions, the smartphone apps can't read a name change on the Custom one. Given that you can only have a single custom schedule, it's not too hard to remember what it does, but it would have been nice if the name change you set on the Controller carried over to the app. Still, with the changes made, the app is now an important part of the home control system and we found that we rarely needed to use our Controller, stashing it away in a cupboard for when we needed to make bigger changes to the heating schedule.
HONEYWELL EVOHOME IFTTT
With the new App, Honeywell also introduced support for If This Then That (IFTTT). In case you haven't come across the system before, IFTTT lets you carry out tasks based on triggers. With Evohome that means, for example, that you can set your heating to turn off when you leave the house, or to turn a room on automatically when you're on your way home from work. As the Evohome IFTTT channel is expanded and upgraded, the possibilities are limitless, making this smart heating system even smarter.
HONEYWELL EVOHOME CONCLUSION
There's no doubting that the Evohome outsmarts the smart thermostats, such as Nest, Hive and Tado. Its zone control gives you more flexibility and means that you're only ever heating the rooms that you need, rather than increasing the temperature of the entire house. This is particularly true once you've got your head around the schedules and have tweaked them.
It's hard to get away from the fact that this system is a lot more expensive than anything else. The starter kit, which includes one relay, the internet gateway and the Controller costs £249. Each Radiator Controller is around £50 - we needed nine, which comes in at £450. Then there's installation, which is really dependent on the complexity of your home, but it'll most likely take around two hours. While you can save money by not installing the Radiator Controllers, we feel as though that negates a large part of the system, so Evohome is definitely best if you go all-in from the start.
As a comparison, Nest, Tado and Hive all come in at under £200. There's an argument to say that Evohome will save you more money, as it's more efficient and zone-based, but it will take a long time to make back the difference over one of the smart thermostat systems.
However, Evohome isn't just about saving money, it's about convenience and comfort. Having individual control over each room is something that no other system offers and it's truly different. Thanks to the thermostats in each room, they're all perfectly controlled. As you can override at any time, you never have to worry about being too hot or too cold. If price isn't an issue, then the Evohome is the ultimate in smart home heating technology.