What Is the Honeywell evohome System?
What you're buying. evohome is a full-system replacement for your existing thermostatic radiator valves and central thermostat. The system centres on a wireless colour-touchscreen controller (the ATP921R3100 or newer ATC928G3000 with built-in Wi-Fi) which communicates with HR92 wireless radiator controllers fitted in place of your existing TRV heads. Each HR92 becomes a zone, with its own temperature sensor and motorised valve actuator, reported back to the controller and cloud.
Resideo claims energy savings of up to 32% annually compared with manual TRVs and a single mechanical thermostat, achieved through room-by-room scheduling and the system's Advanced Load Scaling technology, which optimises boiler run times across zones. The system is OpenTherm-compatible for condensing boilers and also supports heat pumps and underfloor heating circuits.
Controller and HR92 TRV — Hardware Review
The controller is a premium piece of kit by heating-controls standards: a full-colour touchscreen that can sit on a desktop stand or be wall-mounted. The latest generation (ATC928G3000) drops the separate internet gateway in favour of built-in Wi-Fi, simplifying setup considerably. The display is clear and responsive, showing all active zones at a glance with current and target temperatures.
The HR92 radiator controller (model HR92UK) replaces your existing TRV head and runs on two AA batteries. It includes a small LCD screen for local temperature display and manual override, a useful feature if your broadband drops. Build quality is solid — the motorised drive is quiet and the unit fits most RA valve bodies via the supplied adaptors. At around £60–75 per HR92 depending on retailer, equipping a whole house adds up quickly, but the hardware feels durable and appropriately specified for the price.
Compared with competitors like the tado° system, evohome gives you significantly more granular scheduling options and a standalone controller that works without the internet — an important resilience consideration for UK homes. See our tado smart radiator valve review for a direct comparison of the TRV experience.
Professional vs DIY Installation
Self-installation is realistic for anyone comfortable with basic plumbing tasks. The HR92 units screw directly onto existing RA valve bodies using the included adaptor set, and pairing them with the controller is straightforward. You will, however, need to run a wired connection from the controller to your boiler's existing wiring centre or programmer. Honeywell provides clear wiring diagrams, and the controller walks you through commissioning step by step.
That said, many UK installers offer evohome as part of a broader heating controls upgrade, and professional fitting ensures the controller is correctly wired, all zones are commissioned, and the system is tested for OpenTherm compatibility with your boiler. Expect to pay £150–300 on top of hardware costs for a competent installer, depending on zone count. If you are also comparing whole-system smart thermostat options, our best smart thermostat UK guide covers the full market including single-zone alternatives that are considerably cheaper to fit.
Total Connect Comfort App
The app (Total Connect Comfort International, available on iOS and Android) lets you view and adjust every zone's temperature, switch between system modes, and programme schedules for each room independently — up to six time periods per day, seven days a week. It also displays a five-day weather forecast and supports multiple locations if you manage more than one property.
In practice the app is functional rather than polished. It gets the essentials right — zone control is clear, overrides are easy to set, and the scheduling interface is logical once you've spent time with it. The main usability complaints from UK users centre on the initial multi-zone setup being time-consuming (each HR92 must be paired individually) and the lack of geofencing, meaning the system cannot automatically switch to an Away mode when you leave home. For a system at this price point, geofencing is a notable omission.
Alexa and Google Home
evohome works with both Amazon Alexa and Google Home via the official Resideo skill and action respectively. You can ask Alexa or Google to set a zone to a specific temperature or switch system modes by voice. The integration is reliable for basic commands, though the multi-zone nature of evohome means voice control can feel cumbersome compared with a single-zone system — you need to specify both the zone name and target temperature.
Home Assistant Integration
evohome has an official integration in Home Assistant, connecting via your Total Connect Comfort account credentials to the international TCC portal. Once configured, Home Assistant exposes each heating zone as a Climate entity and the domestic hot water controller as a Water Heater entity, allowing full temperature and mode control from the HA dashboard or automations.
The integration supports evohome's six system operating modes (Auto, AutoWithEco, Away, DayOff, HeatingOff, and Custom) and zone-level overrides including FollowSchedule, TemporaryOverride, and PermanentOverride. Temperatures are reported at 0.5°C precision (a vendor API limitation). Schedule editing is not supported through HA — you manage schedules in the TCC app or on the controller — and there is no cooling mode support. For most Home Assistant users these are minor limitations given the level of zone-level control available.
Pricing
The evohome starter pack (controller plus two HR92 TRVs) currently retails at around £180–230 depending on retailer and pack variant. Additional HR92 controllers cost approximately £60–75 each. A fully equipped five-zone home would therefore cost roughly £480–600 in hardware before installation — placing evohome firmly at the premium end of the UK smart heating market.
The Honeywell evohome starter pack — official Resideo product page is a good starting point for price comparison; trade suppliers such as Plumbworld and Plumbnation often undercut Amazon on individual HR92 units.
Best For: Large Multi-Zone Homes
evohome's value case is strongest in homes with four or more radiator zones where occupants genuinely use different rooms at different times — large Victorian terraces, detached four-bedroom houses, or homes with home offices, annexes, or outbuildings connected to the same boiler. The granular scheduling and resilient standalone controller justify the premium in those scenarios.
For smaller homes or those wanting a simpler two-zone setup (downstairs/upstairs), a single-zone smart thermostat paired with basic TRVs will deliver most of the energy-saving benefit at a fraction of the cost.
Verdict
The Honeywell evohome remains the most capable multi-zone smart heating system available in the UK. The hardware is well-built, the Home Assistant integration is solid, and the standalone controller means your heating continues to function intelligently even during broadband outages. Its weaknesses — the dated app, lack of geofencing, and high per-zone cost — are real but largely outweighed by what it does well for the right home. If you have a large property and want room-by-room control with genuine Home Assistant integration, evohome is the system to beat.
Related: Hive vs Tado vs Nest comparison, best smart radiator valves UK, and best smart thermostat UK.
