It's comparatively expensive, but Honeywell's Evohome is the most flexible and smartest home heating system available
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.
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.
When the kit originally launched, the Controller could only communicate via RF with other Evohome components. That means that if you wanted to control your system over the internet, you’d also need to add the optional Gateway product, which was an additional box that plugged into your broadband via an Ethernet controller. However, Honeywell has recently updated the system with a new Controller that has built-in Wi-Fi. Once you’ve connected it to your existing system, you’ve got heating that you control via the internet. We have to say that this new approach is much better, as it gives you a smart system out-of-the-box, with fewer devices to power and at a lower cost. It also means that you shouldn’t be careful when buying: make sure you get the new Controller.
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.
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.