Honeywell Home T6R-HW review
Honeywell Home T6R-HW Wall-Mounted Wireless Heating & Hot Water Smart Thermostat (Y6H920RW5031)
By Tom Calder
The answer to a common and badly served UK problem: a single, sensible thermostat that controls both heating and a stored hot water cylinder. Resideo specifies it for 24–230V on/off and OpenTherm appliances including gas boilers, combis and heat pumps, and for Sundial S-plan, Y-plan and W-plan stored hot water systems with 24V and 230V zone valves, with no separate hub required. Screwfix lists a 5-year manufacturer's warranty for domestic use subject to proof of purchase and terms; the frost protection and holiday mode are built-in functions rather than any external certification.
- Best for
- An S-plan or Y-plan home with a hot water cylinder that needs one thermostat to run both.
- Skip it if
- You want room-by-room zoning
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Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Genuinely controls a stored hot water cylinder as well as heating
- Specified by Resideo for S-plan, Y-plan and W-plan systems, 24V and 230V zone valves
- No hub to buy, and Screwfix lists a 5-year manufacturer's warranty for domestic use
Worth knowing
- Single zone only — there is no radiator valve ecosystem for room-by-room control on this product
- The 2-channel receiver box always requires a 230V supply wired in at the boiler or programmer position
- Ignore the 'suitable for all boilers' retailer wording — Resideo makes no universal claim, and unsupported systems such as solid fuel are out
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Our review
Resideo's two-channel wireless thermostat for homes with a hot water cylinder: a T6R-HW room unit on a powered wall plate, and a receiver box at the boiler or wiring centre that switches heating and stored hot water separately. Its strength is doing the ordinary S-plan or Y-plan job properly with no hub. It suits a conventional or system boiler household that wants one sensible control, not a zoning project.
What it is
The receiver is a 110mm square box, 40mm deep, powered by 230V mains and holding relays rated from 0.5A to 5A resistive. It carries two channels, which is what lets the thermostat run heating and hot water on separate schedules, and Resideo's wiring diagrams show it dropped straight into a Sundial S-plan or Y-plan with the existing cylinder thermostat and zone valves, or onto a combi or OpenTherm boiler with two wires. In this wall-mounted kit the thermostat sits on a plate with its own 230V power supply, needing a back box at least 40mm deep; the table-stand version, Y6H920RW4026, plugs into a socket instead. The pair arrive pre-bound and talk on 868MHz, with Resideo quoting 30m range inside a home.
Hot water and heating control
Heating runs on a daily or 5/2 schedule with up to six periods a day, and hot water gets its own schedule: three on periods a day, which Resideo's product page counts as six on/off periods. The thermostat can act as the temperature sensor for an S-plan or Y-plan, so one unit replaces the old programmer and room stat. On an OpenTherm boiler the receiver modulates, reads supply and return temperatures from the boiler, and switches to calculated on/off cycling when demand drops very low, which Resideo calls low-load control; Resideo rates the product ErP class V. Optimum start learns how long the house takes to warm and optimum stop switches off a little early; the room unit's off position holds 5°C frost protection, and the installer can lower the top limit from 35°C to as little as 21°C. Geofencing comes through the Resideo app, and Resideo says the T6R works with Apple HomeKit, Amazon Echo, Google Home and IFTTT.
How it compares
The tado X starter kit also does two channels and OpenTherm, adds Matter and a rechargeable thermostat, and leads to tado's radiator valves, but its warranty is two years. Drayton's Wiser Multi-Zone Kit 2 (2nd gen) brings hot water plus two radiator thermostats for room control, though Drayton specifies relay switching only. The evohome pack is Resideo's own route to 12 zones, at engineer prices. See our comparison.
Living with it
Resideo's installation sheet is blunt: it must be installed by a competent person, and both the receiver and the wall plate are mains wiring. The receiver box is rated IP30, and the thermostat should sit at least 1.2 to 1.5m off the floor, away from draughts, sunlight and heat sources. A failsafe option makes the receiver cycle the boiler 20% on and 80% off if it loses the thermostat for more than an hour, so a dead room unit does not leave the house cold or the boiler running flat out. Y6H920RW5031 is on Resideo's five-year warranty list, running 60 months from the manufacturing date code; the policy is written for the trade buyer, who Resideo expects to pass equivalent cover on, and the retailer we track quotes five years for domestic use with proof of purchase.
Our verdict
Buy it if you have a cylinder, zone valves and a boiler that fits Resideo's on/off or OpenTherm specification, and you want heating and hot water on proper schedules from one unit with a long warranty. Look elsewhere if you want room-by-room control, because this product has no radiator valve family; or if you have 240V electric heating, which Resideo rules out. If the boiler itself is unreliable, read boiler stopped working in the cold before spending on controls.
A researched review, built from the maker's specs, manual and UK listings; facts checked 21 Oct 2026. Sources: Resideo UK: Y6H920RW5031 T6R-HW smart thermostat wall mount kit with hot water; Honeywell Home T6R-HW installation guide (32308181-020); Honeywell Home T6R wall mount installation guide (32308181-028); Honeywell Home T6 and T6R specification sheet; Resideo UK: T6R product line page (app, Apple Home, Alexa, Google Home, IFTTT); Resideo 5 year warranty policy and eligible product list (September 2024).
Who shouldn't buy this
Don't buy it if you want room-by-room zoning — evohome, Drayton Wiser and tado all support radiator valves and this does not.
Key specs
| Works with | 24–230V on/off and OpenTherm boilers, heat pumps; S/Y/W-plan |
| Control | OpenTherm or relay; genuinely controls stored hot water |
| Zoning | Single zone only — no radiator valve ecosystem |
| Fitting | No hub; 2-channel receiver needs a wired 230V supply |
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the UK price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for Most UK homes — including heat pumps and cylinder systems — that want hot water control without buying a hub.
as of 5 Nov 2026, 22:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Best for Room-by-room control on a combi boiler without paying whole-house-system money.
as of 5 Nov 2026, 22:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Best for Room-by-room control in a home with a hot water cylinder, without a whole-house engineer's system.
as of 5 Nov 2026, 22:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.Questions
Can the Honeywell T6R-HW control a hot water cylinder?
Yes. Resideo specifies it for Sundial S, Y and W-plan systems with stored hot water and zone valves, and the receiver's second channel gives hot water its own schedule of three on periods a day.
Does the T6R-HW need a hub?
No. The thermostat and receiver are pre-bound over 868MHz, and the thermostat joins 2.4GHz Wi-Fi directly for the Resideo app.
Is the T6R-HW thermostat battery powered?
No. It runs on 5V DC: in this wall-mounted kit from a 230V power supply behind the wall plate, and in the table-stand version from a plug-in adapter.
Does the T6R-HW work with OpenTherm?
Yes. Resideo lists gas boilers, combis and heat pumps that take a 24 to 230V on/off signal or OpenTherm. On OpenTherm the receiver modulates the boiler and shows its supply and return temperatures.
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