Honeywell Home evohome Wi-Fi Connected Thermostat Pack (ATP921R3100) review
A large or awkward home being zoned properly by a heating engineer.
By Tom Calder · Updated 24 July 2026 · Price checked against our tracker
The most capable system here — Resideo quotes up to 12 individually time- and temperature-controlled heating zones plus a separate domestic hot water zone, and the broadest system support of anything on this page, covering most boiler types, heat pumps, district heating, pellet burners and S-plan or Y-plan zone-valve setups. But the pack as sold is a controller, a table stand, a power lead and one wireless relay box: no radiator controllers, no OpenTherm and no hot water control. Judge it as the first component of a professionally installed whole-house system, not as a £215 thermostat.
Around £215 inc VAT — confirmed in stock at The Smart Thermostat Shop at £213.99, reduced from £239.99, on 24 July 2026. Pricing across UK plumbing merchants is unusually wide for this SKU, from roughly £182 to £301 inc VAT in a single check, so shop around rather than trusting one listing. Critically, this is the controller pack only: adding radiator controllers pushes real-world spend well past £330.
ⓘ We may earn a commission when you buy through our links — it never affects what we recommend, and we buy everything we test.
- Up to 12 heating zones plus a separate hot water zone, on Resideo's own figures
- Broadest system support here — most boiler types, heat pumps, district heating, S-plan and Y-plan
- The only product on this page designed from the outset to grow to whole-house zoning
- The pack includes no radiator controllers at all, so it does not deliver multi-zone heating as sold
- OpenTherm needs the separate R8810A1018 bridge, and hot water needs the ATF500DHW kit or a CS92A cylinder thermostat
- Realistically a qualified engineer's job — UK quotes for whole-system fitting run roughly £600 to £900 and up
Key specs
| Works with | Most boilers, heat pumps, district heating; S-plan and Y-plan |
| Control | Relay as sold; OpenTherm and hot water need extra hardware |
| Zoning | Up to 12 heating zones + 1 hot water; controllers extra |
| Fitting | Engineer's job; whole-system fitting quoted c.£600–£900+ |
Our rating is a considered spec-and-evidence verdict: we verify every specification against at least two independent sources, track the UK price daily, and say plainly who a product isn't for. Commissions never change a rating. Read the full methodology →
Alternatives to consider
Want this cheaper?
We track this price daily. Leave your email and we'll tell you when it drops — nothing else.