Smart Controls Comparison
Honeywell vs Heatmiser — Which Smart Thermostat for Your London Home?
Two excellent zoning systems — but built for different heating setups. Our London engineers explain which is right for you.
Honeywell evohome is best for radiator zoning — its smart TRVs give best-in-class individual room-by-room control without pipework changes. Heatmiser is purpose-built for underfloor heating, supporting up to 32 zones with built-in floor sensor input. For London homes with existing radiators, choose Honeywell; for whole-house UFH, choose Heatmiser. Both support OpenTherm for modulating boiler control.
For London homeowners wanting room-by-room temperature control, the choice often comes down to Honeywell evohome and Heatmiser. Both are excellent multi-zone systems — but they shine in different scenarios. Getting this wrong can mean an expensive retrofit later, which is why we help clients choose the right system before any work begins.
Side-by-Side Comparison
| Feature | Honeywell | Heatmiser |
|---|---|---|
| Primary Use | Radiator zoning (room-by-room) | Underfloor heating & zones |
| Underfloor Heating Control | Supported — but not primary focus | Native — industry leading |
| Multi-Zone Control | Up to 12 zones (evohome controller) | Up to 32 zones (neoHub) |
| Individual Radiator Control | Yes — via smart TRVs (best-in-class) | Yes — via zone valves |
| App Control | Honeywell Home app | Heatmiser Neo app |
| Google Assistant | Yes | Yes |
| Amazon Alexa | Yes | Yes |
| Apple HomeKit | No | Yes |
| OpenTherm Support | Yes (native) | Yes |
| Floor Sensor Input | No — not available | Yes — built into NeoStat |
| Geofencing | Yes (app-based) | Yes (app) |
| Energy Reports | Detailed — per-zone usage | Basic |
| Wiring Complexity | Moderate — smart TRVs on each radiator | Standard — engineer install |
| Typical Cost London | £800–£2,500 (multi-zone radiators) | £1,200–£3,500 (multi-zone UFH) |
| RARE Recommendation | Best for radiator zoning | Best for UFH & precision |
Honeywell evohome
Best for: radiator zoning, room-by-room control
Best-in-class individual radiator control via smart TRVs
Room-by-room zoning without pipework changes
Native OpenTherm support for modulating boilers
Detailed per-zone energy reporting
Reliable, well-established brand with strong UK support
Not designed for underfloor heating — no floor sensor
Maximum 12 zones vs Heatmiser's 32
No Apple HomeKit integration
Smart TRVs add cost per radiator
Heatmiser
Best for: underfloor heating, multi-zone precision
Purpose-built for underfloor heating — unmatched UFH control
neoHub allows up to 32 independent zones on a single hub
Built-in floor sensor input protects timber and stone finishes
Apple HomeKit integration supported
RARE engineers are Heatmiser-certified specialists
Higher cost for multi-zone setups
Less intuitive app vs Honeywell Home
Individual radiator control requires zone valves, not wireless TRVs
RARE Engineer Verdict
Our Recommendation
If you have radiators and want room-by-room control — choose Honeywell evohome. The smart TRV system lets you control each radiator individually without changing pipework, and the OpenTherm integration delivers genuine modulating control. For London townhouses with existing radiator systems, it's our go-to recommendation.
If you have underfloor heating — choose Heatmiser. It's purpose-built for UFH control, supports up to 32 zones via a single neoHub, and includes a floor sensor input that Honeywell simply doesn't offer. For the kind of whole-house UFH installations we do in Knightsbridge and Belgravia, there's no competition.
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