Honeywell has been making heating controls for decades, and its smart thermostat range reflects that heritage. Rather than flashy features for their own sake, Honeywell focuses on reliability, compatibility with UK boilers, and precise temperature control.
For UK homes with combi boilers, the Honeywell range, from the T6 to the T9 and Evohome, covers everything from simple scheduling to full, professional-grade multi-zone heating.
This guide walks through the Honeywell smart thermostat range first, then compares them to alternatives like Nest and Tado at the end for context.
Honeywell’s Smart Thermostat Philosophy (Why They Feel Different)
Honeywell designs thermostats around a simple idea.
Predictable control beats clever automation when it comes to heating comfort.
Instead of relying heavily on AI learning, most Honeywell systems prioritise:
- Stable temperature control.
- Accurate sensors.
- Clear schedules.
- Strong boiler modulation, especially with OpenTherm.
That makes them particularly well-suited to UK combi boilers, where smooth modulation and consistent flow temperatures matter more than aggressive on-off cycling.
Honeywell T6 / T6R: The Everyday Smart Thermostat
The Honeywell T6, and wireless T6R, is the most common entry point into Honeywell’s smart ecosystem for UK homes.
What It’s Designed For
The T6 is built for households with fairly regular routines who want better control than a basic programmer, without handing decisions over to an algorithm.
It delivers:
- 7-day programmable schedules.
- Geofencing to reduce heating when the house is empty.
- Optimum Start, heating early so rooms reach temperature on time, not late.
- Strong OpenTherm boiler modulation.
There’s no learning behaviour, which many users see as a benefit rather than a limitation.
Real-World Performance
In practice, the T6:
- Keeps temperatures stable.
- Avoids overshooting and boiler short-cycling.
- Typically saves 10 to 15% compared with manual or basic digital controls.
That’s around £100 to £150 a year in a typical UK home upgrading from a simple timer, broadly in line with the Energy Saving Trust‘s general guidance on savings from smart heating controls.
Best Suited To
- Combi boiler homes.
- Budget-conscious upgrades.
- People who like predictable schedules.
- Landlords and rental properties.
Honeywell T9: When One Room Is Always Colder Than the Others
The Honeywell T9 builds on the T6 by introducing remote room sensors.
Instead of relying on one thermostat location, the T9 can:
- Sense temperature in multiple rooms.
- Prioritise the coldest space.
- Balance heating more evenly across the home.
This makes a real difference in UK houses where:
- Bedrooms are colder than living areas.
- Extensions heat differently.
- Upstairs and downstairs behave inconsistently.
T6 vs T9 in Simple Terms
| Feature | T6 / T6R | T9 |
|---|---|---|
| Control style | Single reference room | Multi-room sensing |
| Sensors | None | Remote sensors included |
| Zoning | Single zone | Pseudo zoning |
| Typical cost | £160 – £200 | £200 – £300 |
| Best for | Straightforward layouts | Uneven heating |
If a home heats evenly already, the T6 is usually enough. If one room dictates comfort for the whole house, the T9 is worth the step up.
Honeywell Evohome: Full Smart Zoning (The Heavyweight Option)
Honeywell Evohome sits in a different class entirely.
Rather than controlling the boiler as one zone, Evohome creates independent heating zones for each room using wireless radiator controllers, with no rewiring required.
What Evohome Does Differently
- Each radiator becomes its own thermostat.
- Rooms follow independent schedules.
- Boiler output is matched to real, room-by-room demand.
This is one of the most precise ways to control heating in larger UK homes.
Typical Installation Process (UK)
- Survey boiler compatibility, with OpenTherm working best.
- Install the Evohome controller and boiler relay.
- Fit smart radiator heads (HR92s).
- Configure zones and schedules.
- Commission and test the system.
Cost Reality (2026 UK)
| Setup | Typical Total Cost |
|---|---|
| Basic Evohome | £300 – £400 |
| 8-zone system | £800 – £1,200 |
| 12+ zones | £1,300 – £2,000+ |
Typical savings sit around 15 to 20% on the heating bill, sometimes exceeding 30% in large or previously poorly zoned homes, but Evohome is overkill for small properties.
Reliability & Support (Why Engineers Like Honeywell)
From an installer’s perspective, Honeywell systems are:
- Stable.
- Rarely prone to dropping connection.
- Consistent across firmware updates.
They don’t change app layouts as often as some consumer-focused brands, which reduces user confusion and repeat callouts.
For landlords and long-term homeowners, that reliability matters more than novelty features.
How Honeywell Compares to Nest and Tado (Quick Context)
Once the Honeywell range makes sense, the alternatives are easier to place.
Honeywell vs Nest
- Nest focuses on automation and learning.
- Honeywell focuses on control and predictability.
Nest often saves more in chaotic households. Honeywell wins where people want consistent, explainable behaviour.
Honeywell vs Tado
- Tado excels at radiator-based zoning with smart TRVs.
- Honeywell Evohome offers more precise, professional-grade zoning.
Tado suits mid-sized homes, while Evohome suits larger ones.
Boilers2Go Verdict
For reliable, no-nonsense smart heating, Honeywell’s range is hard to beat.
- T6: for affordable, dependable control.
- T9: for homes with uneven temperatures.
- Evohome: for full room-by-room precision.
Nest and Tado have their place, but Honeywell remains the go-to choice when stability, boiler compatibility, and long-term performance matter more than novelty features.
A quick compatibility check against the specific boiler and home layout before buying saves time, money, and frustration further down the line.
Related Reading
For homes with underfloor heating or other wired zone control needs, Eph controls for central heating covers an alternative approach to multi-zone control worth comparing against Evohome.
Those exploring other manufacturers’ thermostat ranges may also find smart thermostat features for households useful, since it looks at what to expect from a different brand’s smart control lineup.
FAQs
Do Honeywell thermostats work with all UK combi boilers?
Most Honeywell thermostats work with the vast majority of UK combi, system, and regular boilers, though the best results come from boilers with OpenTherm support, which allows modulating control rather than simple on-off switching.
A quick compatibility check against the specific boiler model before buying avoids a mismatch, since older or budget boilers without OpenTherm still work but won’t get the full benefit of smooth modulation.
What is OpenTherm and why does it matter for Honeywell thermostats?
OpenTherm is a communication protocol that lets a compatible thermostat talk directly to the boiler, adjusting flow temperature precisely rather than just switching the boiler on or off.
Honeywell’s range leans heavily on this for its smooth modulation and stable temperatures, so pairing it with an OpenTherm-enabled boiler gets noticeably better results than an on-off-only setup.
Can I install a Honeywell smart thermostat myself?
The thermostat unit itself is often straightforward to fit, but the boiler-side relay or control box usually needs a Gas Safe registered engineer, particularly on gas combi boilers.
Evohome installations, which involve multiple radiator valves and zone configuration, are best left to a professional engineer from the outset rather than attempted as a full DIY project.
Is the T9’s multi-room sensing the same as full zoning like Evohome?
No, the T9 senses temperature across multiple rooms and adjusts the whole system based on the coldest space, but it still controls one shared heating zone rather than each room independently.
Evohome goes further by giving each radiator its own controller, so different rooms can genuinely run to different schedules and temperatures at the same time.
How long does Evohome take to pay for itself?
In a large or previously poorly zoned home, typical savings of 15 to 20% on the heating bill mean an Evohome system usually pays for itself within 3 to 5 years, with well-zoned larger properties sometimes seeing savings above 30%.
Smaller, evenly heated homes are less likely to see a quick payback, since there’s less inefficiency for the zoning to correct in the first place.
Do Honeywell thermostats work with Alexa or Google Home?
Yes, the T6, T9, and Evohome ranges all support voice control through Amazon Alexa and Google Home, alongside their own dedicated apps.
Apple HomeKit support varies by specific model, so it’s worth checking the exact product listing if that particular ecosystem matters.
What happens if the WiFi goes down, can Honeywell thermostats still control the heating?
Yes, Honeywell thermostats continue to run their existing schedule locally even if the home WiFi connection drops, since the core scheduling function doesn’t depend on an internet connection.
Remote access, geofencing updates, and app control are what’s lost during an outage, not the heating itself, which keeps following its last known programme.
Is Evohome being replaced or discontinued?
Evohome remains in Honeywell’s active range and continues to receive firmware updates, though the core hardware design has been broadly unchanged for some years now.
Newer multi-zone competitors have emerged since its launch, so it’s worth comparing current alternatives alongside Evohome before committing, particularly for anyone prioritising the newest app features over proven zoning reliability.
I’m Penny North, a home energy heating expert. My mission is to demystify new boilers and complex heating systems to help you achieve a warm, cosy home with lower energy bills and a smaller environmental footprint.