Honeywell Evohome full review
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At its most basic, Evohome is just like Nest. If you want to, you can buy a 'single zone connected thermostat pack' (Y87RF2024/RFG100 ) for under £140, install it yourself and it will work almost exactly as Nest and Netatmo's thermostats do.
This isn't Evohome, though. It's best thought of as the most basic setup that could be used in an Evohome system. The pack comprises a T87RF wireless room thermostat, a BDR91 wireless relay and an RFG100 'mobile access kit' which connect to your router and makes the system controllable via the internet and Honeywell's Total Connect Comfort app.
Such systems measure the temperature at one location (typically in the hall, just like your old thermostat) and heat the whole house until the thermostat reaches the set temperature, called the setpoint in heating jargon.
To avoid any one room becoming too hot, these systems rely on you already having thermostatic radiator valves (TRVs) installed. These shut off the radiator when the desired room temperature is reached, although you only have a dial which runs from 1-5, so you have to figure out which setting is best by trial and error. Your radiators may not have TRVs, of course. They could have a simple knob which you set manually to fully open, fully closed or somewhere in between.
Where smart heating systems really get smart is when you replace these knobs or TRVs with smart TRVs. Like 'dumb' TRVs they have built-in thermostats but the difference is that they can be controlled remotely. This is a huge advantage as it means you can have control over the temperature of each room without having to walk around your home turning individual radiators up or down manually.
The bad news is that smart TRVs are expensive. If you have 10 radiators you want to control, that's £500 before you've added the cost of the controller, relay and installation.
This is why it makes sense to only control those radiators in rooms you spend the most time in. Smart TRVs can also be grouped into 'zones', so you could have an upstairs zone and downstairs zone, and set each to different temperatures at different times of day. You might want to group all bedrooms as a zone, for example, and set it so they're only heated first thing in the morning and just before everyone goes to bed.
While such a setup can save money in the long run, it takes a big initial investment. You can also buy the evohome Security system which uses the same app as the heating system.
One of the more recent updates from Honeywell is that two T87RF single-zone thermostats can be linked via one RFG100 gateway and used to control two separate zones. This gives you multi-zone control without the expense of buying the touchscreen controller or smart TRVs. However, your heating system will need to have two separate zones for this to work. That means having two heating valves connected to your boiler so that, for example, upstairs radiators and downstairs radiators can be turned on separately.
Honeywell also introduced an updated touchscreen controller with built-in Wi-Fi. This removes the need for the RFG100 internet gateway as the controller can communicate directly with your router. We're told that the screen is identical to the non-Wi-Fi model and that the wireless range is exactly the same. There's no change to the interface, menus or features and the price of the starter kit remains the same at £249.
There are of course, other smart thermostats, so check out our list of the best smart heating systems to find alternatives.
Honeywell Evohome review: Test system
We had an Evohome system installed into a large house in order to test out its full capabilities, controlling both radiators and underfloor heating (UFH). Honeywell has a system builder tool which helps you work out which components you need for your home: you tell it how many rooms you want to control, the type of heating in those rooms and whether you have a combi boiler, water tank or other heat source.
In our test home the system builder advised three room thermostats, 10 smart TRVs, a UFH controller, hot water kit, mobile access kit and a base pack (the touchscreen controller). Here's all the stuff you'll actually see:
The UFH controller (£285 inc VAT) can handle five zones, but is upgradeable to support eight zones for an extra £75 if necessary. To save money, you can group UFH actuators into one zone: you don't need to have each one on a separate zone. The UFH controller works with the T87RF wireless room thermostats (£79.99 each) to maintain a constant temperature in those rooms or zones.
Such a system needs professional installation which took a full day. Not all our radiators had compatible valves for the TRVs, so some had to be changed over using pipe-freezing packs. The existing UFH controller had to be swapped out for the Honeywell one, and the sensor and relays installed for the boiler and hot water tank.
Despite thick stone walls and long distances from the EvoHome controller to the furthest TRVs, there were no wireless connectivity problems. We did have to move the RFG100 as the controller couldn't connect to it where we originally placed it next to the broadband router. However, using a pair of existing powerline adaptors we were able to relocate it to a more central position in the house.
Honeywell Evohome review: Features
The Evohome controller does the bulk of the work and lets you program a schedule as well as adjusting zone temperatures whenever you want to make a change. It can also act as a room thermostat on its own. The controller can be wall mounted, but since it requires mains power most people will prefer to leave it on its tabletop stand.
There's an internal battery so you can slide it off its stand and use it completely wirelessly, but it's more convenient to use the iOS or Android app. Unfortunately there are only unofficial apps for Windows Phone and Blackberry which lack the full set of features.
Using the controller or app you can create zones by grouping TRVs and thermostats. This allows you complete freedom to set up the system as you like. The controller supports up to 12 zones which is enough for most people, although it becomes restrictive if you have underfloor heating in addition to lots of radiators and want to control everything separately. It's the most customisable smart heating system we've tested.
The TRVs have more settings than you'd imagine, too. Their displays are on a hinge so they can be angled upwards to make it easier to read, and they're also backlit. Using the built-in controls the temperature can be overridden manually, but there's also a lock function to prevent kids (or guests) from changing the temperature. It's also possible to set upper and lower limits, as well as recalibrating the thermostat so the temperature reads higher than it actually is, for example.
They take two AA batteries which should last a year, and you can even tell the TRV which type of batteries are installed. As with the Heat Genius system, they can detect if a window is open and automatically shut off the radiator to prevent wasted heat.
If they have to be installed inside a radiator cabinet, or in a cramped corner, you can choose to monitor temperature from a room thermostat instead of using the TRV's stat.
Both the app and controller display the temperatures for each zone and you can rename each zone to match your home. If you have a hot water tank, you can also monitor the water temperature. A Quick Actions button brings up options to turn the heating off, tell the system you're away (and therefore maintain a minimum temperature), have a day off (ignore the usual schedule and keep the heating on) and a handy Economy button which lowers all zones by 3 degrees.
Naturally, everything is customisable so you can set the periods for which quick actions apply and their associated temperatures.
Creating a schedule can be done in several ways. A wizard guides you through the process, or you can do it manually. As you'd expect, you can have separate schedules for each day and each zone.
If someone overrides the temperature using a room thermostat, the controller or a TRV, it will revert to the set temperature at the next heating period.
Many people worry about what happens if their internet connection goes down. With EvoHome - as with all internet connected thermostats - you lose remote control from the app. However, the controller will stick to the schedule and you'll still be able to use the TRVs, thermostats and controller to adjust the temperature. You'll receive an automated email telling you the connection has been lost, and another when it is restored.
Honeywell Evohome review: limitations
While Evohome is the most comprehensive system we've seen (few rivals can control hot water - although Hive can) and it doesn't tick every last box.
One such box is that there's no presence detection. If you go out and forget to change the schedule, the system will heat the house regardless. Those with a regular routine won't be affected, but if you never know when you'll be in or out then Tado or indeed Honeywell's own Lyric system could be a better choice for smaller homes.
The good news is that you can get around this limitation thanks to Evohome's support for IFTTT. Using the free app you can set up any triggers you like, so it's possible to turn off the heating when you leave the house by virtue of your phone's GPS location.
For some people, manual scheduling is exactly what they want: they have complete control over their heating schedule and there isn’t a "system with a mind of its own". If you want to set a heating period of 20 degrees from 7am until 9am, the boiler will fire up at 7am and maintain that temperature in that zone until 9am.
However, Evohome is far from dumb. If you prefer, you can use the Optimal Start and Stop feature which will ensure each zone reaches the set temperature by the start of the heating period. This means that if it's cold outside and the room is a few degrees cooler than usual the boiler will fire up earlier to get the room up to temperature in time.
Since EvoHome learns how long it takes for each zone to heat up and cool down, it can also stop the boiler early rather than continuing to heat right up until the end of the heating period. For example, if you set a temperature of 19 degrees until 11pm, EvoHome will know that it can turn off the boiler at 10:30 and the zone will still be 19 degrees at 11pm.
There's no support for air conditioning systems, but there's no need for this in the UK, so it's not a deal breaker by any means.
Honeywell Evohome review: long-term update
We've now been trialling Evohome for over a year and while it has seen little use during the summer beyond hot water control, it has been very reliable. Despite the thick stone walls in the old part of the house, there have been no issues with signal loss. Well, initially we did get repeated emails about the gateway losing communication with the controller, but a simple move of the gateway from floor- to desk level fixed that.
As well as the handy ability to turn radiators off without having to walk round the house, it's also useful to be able to monitor the temperature of guest bedrooms and ensure they're warm enough without having to ask. And guests can use the TRVs to turn up the heat if they want to - this overrides the scheduled temperature until the next period. Also, the 'off' function on the TRV comes in handy for those who like to sleep with the window open. Since there are motors in the TRVs, they do make a noise when they adjust the valve, and this is worth explaining to any guests.
The app, as we've said, is well designed. It's easy to see the current hot water temperature and easy to adjust scheduled heating temperatures up or down.
Honeywell Evohome review: bottom line
While you'll get incredibly fine control over the temperatures in each zone, having several zones means the price quickly scales to a point where it will be years before you break even and begin to save money.
But despite the cost, EvoHome is a fantastic system for those who want to control temperatures in different rooms, have control over their hot water and also those with underfloor heating. It's particularly good for larger homes with few occupants where you might want to heat only certain rooms at certain times.
It's very easy to use, even for technophobes and although it can take a while to set a schedule in the first place, making tweaks is quick and simple.
The Base Pack (touchscreen controller and boiler relay) is good value at around £160, but when you start adding the TRVs at £50 each, underfloor heating controllers at £270, internet gateway at £50, room thermostats at £140, hot water sensors at £80, costs mount up fast. As with Heat Genius, you can easily spend over £1000 including installation. Twice that in our case.
There's a sweet spot for some if you can get away with a small selection of TRVs, a controller and internet gateway. And you'll certainly save money if you're prepared to install it yourself. Then, when funds allow, it's easy to expand the system.
If money is no object, we can highly recommend Evohome. For virtually everyone else, a Hive or Nest with dumb TRVs is a more affordable option.
Honeywell Evohome: Specs
- Modular smart heating system
- App available for iOS and Android
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