Best Smart Heating for Home Assistant UK 2026: which brand to buy

If you're buying a smart thermostat in the UK in 2026, four brands cover 95% of homes: Tado, Hive, Drayton Wiser and Honeywell Evohome. They all say "compatible with Home Assistant" on the box. Only two of them work properly with it without ongoing cloud headaches. This guide is the broad overview — the per-brand verdict, the buy criteria, and links to the dedicated head-to-head comparisons where you've already narrowed your shortlist to two.

TL;DR — buy this one

For most UK homes in 2026, Drayton Wiser is the pick if you care about Home Assistant integration quality. It has a local API on the Wiser Heat Hub (the others are cloud-only), the community HA integration is mature and actively maintained, multi-zone TRV setups are still cheaper than the alternatives (Wiser TRVs are around £54 each at Screwfix vs £80 for Tado), and the kit doesn't fight you when an internet outage takes the cloud down.

Tado is the second-best choice if you want a more polished app and don't mind the cloud dependency. Excellent multi-zone, supported HA integration, but Tado introduced API tiering on 7 September 2025 — read the gotchas section before buying.

Hive works with HA but the cloud-only architecture means an outage at British Gas takes your heating offline at the same time. Not what you want for the system that decides whether your house is cold. Hive also shut down several other product lines (Nano 1 Hub, Hive Camera, Boiler IQ, View cameras, HomeShield) on 1 August 2025 — that pattern of product retirements matters when you're choosing kit for the next 5+ years.

Honeywell Evohome is the enthusiast premium pick — superb hardware, complex install, expensive. If you're already deep in HA tinkering, it's wonderful. If you're not, skip it.

At-a-glance comparison

Why "compatible with Home Assistant" doesn't tell you much

Every smart-heating brand will tell you they integrate with Home Assistant. The honest version is that integration quality sits on a spectrum from "first-class local API designed for this kind of use" to "we have a community integration that occasionally breaks when our cloud team ships a release". The brands above span the whole range.

The differences come down to four things:

Local vs cloud API. A smart thermostat is the device that decides whether your radiators turn on. If that decision goes through a cloud server in another country, then any outage there — Cloudflare wobble, AWS region issue, the manufacturer's own deploy — becomes a heating outage in your house. A local API means HA talks to the hub directly over your home network. Faster, more reliable, doesn't break when the manufacturer goes bankrupt.

Multi-zone support. Single-thermostat systems heat the whole house to one temperature. Multi-zone (using TRVs on each radiator) lets you keep bedrooms cool overnight while the living room is warm in the evening. For HA users this is the killer feature, because once HA can address each room independently, you can build automations that follow people around the house.

API stability. Some brands ship cloud-API changes regularly that break community integrations. Others are stable. The pain of an integration breaking on a Saturday evening when you're trying to bump the temperature for dinner guests is real, and it correlates strongly with cloud reliance.

Replacement hardware availability. Years from now, will you be able to buy a replacement TRV head when one fails? Tado and Honeywell are deep into the UK channel and stocked everywhere. Drayton Wiser is sold by Screwfix and Toolstation. Hive is mostly British Gas channel. None are at risk of disappearing in 2026, but compatibility-with-future-product is a hidden long-term cost.

The contenders — quick verdict

Brief per-brand verdicts below. For deeper head-to-head comparison once you've narrowed to two brands, the dedicated comparison guides go further:

• Drayton Wiser vs Tado — the most common shortlist for HA-focused buyers
• Tado vs Hive — the most common shortlist for mainstream buyers

Drayton Wiser — the HA-friendliest pick

The default recommendation for anyone buying smart heating specifically because they want it to play nicely with Home Assistant. Local LAN API on the Wiser Heat Hub means HA talks to it directly without cloud round-trips. Multi-zone TRVs land around £54 each at Screwfix (cheaper than Tado). Boiler relay is wired, not wireless-only, so RF interference can't take it down. Downsides: utilitarian app, bulkier TRVs, no built-in geofencing (you build that in HA).

Buy if: you want HA to work without fighting cloud APIs, you have several rooms to zone, you're OK with utilitarian aesthetics.

Tado — the polished cloud pick

Tado is the most-installed smart heating brand in the UK. Tado V3+ is the established line (cloud-based, mature tado HA integration in core). Tado X is the newer Matter-over-Thread line, which HA controls locally through the Matter integration — meaningfully better for HA-focused buyers.

Important 2025 change: on 7 September 2025, Tado introduced subscription tiers. The free tier caps API access at 100 calls/day — too few for normal HA polling. The Auto Assist subscription (£2.99/month or £30/year) lifts that limit and unlocks geofencing automation. Budget for it if you want HA polling to work reliably on V3+.

Buy if: you want the polished app, you'll go with Tado X for the local Matter path, and you're OK budgeting Auto-Assist on V3+ purchases.

Hive — works, but be honest about the trade

British Gas-owned. Cloud-only with a documented history of multi-hour outages. HA integration is in core but inherits the cloud dependency. Several other Hive product lines (Nano 1 Hub, Hive Camera, Boiler IQ, View cameras, HomeShield) were retired on 1 August 2025 — a pattern that matters when you're choosing kit you'll keep for 5+ years. Also: check who owns your Hive account if it was installed under a British Gas service contract.

Buy if: you've already got Hive that's working, or you're a British Gas customer getting a discounted bundle.

Honeywell Evohome — the enthusiast premium

The original UK multi-zone system; still the most capable and most expensive. Per-room TRVs, zone-aware boiler modulation, modules for hot water and underfloor heating. Core evohome integration uses Honeywell's cloud and has had API churn that's broken HA integration multiple times — recovery is usually quick but the wobble is real.

Buy if: you want the most capable hardware, you have a complex install (multiple zones, hot water cylinder, mixed boiler/UFH), and you're already an HA enthusiast.

What about Nest, Aqara TRVs and Heatmiser?

Nest: Google killed off the local Nest API years ago. The current nest integration in HA uses Google's restricted Cloud-to-Cloud framework via the Smart Device Management API, which Google has been quietly de-prioritising. Functional today, uncertain for the long term. Don't buy Nest specifically for HA in 2026.

Aqara TRVs (lumi.airrtc): These are Zigbee-direct TRVs that talk to your existing Zigbee coordinator (e.g. the ZBT-2) without any vendor cloud. Cheap (~£35 each), local-only, work great as part of a HA-driven heating system. The catch: there's no central thermostat or boiler control — you control radiators individually but not the boiler. That's fine if you're using them alongside an existing wireless thermostat, problematic if they're the whole system. Best for: per-room scheduling on top of an existing thermostat, or rooms where the existing thermostat doesn't reach.

Heatmiser: Niche, mostly used in underfloor-heating systems. Excellent local API, well-supported in HA via the community heatmiserV3 integration. If you have UFH and an existing Heatmiser setup, keep it. Otherwise not the obvious starting point.

Multi-zone setup — the hidden cost

When pricing smart heating, the headline number is the hub + thermostat starter pack. The actual cost for most homes is multi-zone TRVs, which add £30–£80 per radiator depending on brand. A typical UK 3-bed house has 8–12 radiators. At £80 each (Tado X), zoning the whole house adds £640+ to the buy. At £31 each (Drayton, Screwfix), you're at £250. At £75 (Honeywell HR92UK), £600.

This is why the brand choice often comes down to per-TRV cost more than per-thermostat cost. Hub + boiler control are 5–10% of the lifetime hardware spend; TRVs are most of it.

A practical compromise: zone only the rooms that benefit from individual control. Bedrooms (cool overnight, warm in the evening) and the living room (warm in the evening, cool during the day) typically pay back zoning fast. Hallways, bathrooms and utility rooms often don't — leave the existing manual TRVs there and save the money.

Or skip all this

If you'd rather not pick a brand, source the hub, install the kit, configure HACS, set up the integration, build the per-room schedules, and keep the integration running through API changes — that's exactly what habbb does.

We ship a pre-configured Home Assistant hub for £150 plus £30/month managed service. New customers can also choose Bring Your Own HA at £40/month if you've already got HA running — the £10/mo premium covers the discovery cost of adopting a non-standard install. Either way, the heating-system integration is part of what we set up: we'll configure your Drayton Wiser, Tado, Hive, Evohome or whatever you've got, build the per-room automations, and fix things when integrations break — without you having to find out about the API change in the first place.

We don't sell the heating hardware. Buy it from your preferred UK retailer (we're vendor-agnostic), then we handle the rest.

See what's in the habbb kit

Common questions

Which one is cheapest to run with Octopus Agile? Drayton Wiser, because the local API means HA can read prices and adjust setpoints in real-time without cloud round-trips that occasionally fail. Tado works too but every command is a cloud hop. The Octopus Agile guide covers the automation side.

Can I use one brand for the boiler and another for TRVs? Technically yes, practically no. Each brand's TRVs only talk to that brand's hub, so mixing means running two parallel hubs. Stick with one ecosystem unless you have a very specific reason.

What about heat pumps? None of these four brands handle heat pumps natively in 2026. If you have a heat pump, look at Octopus Cosy (tariff side) and your heat pump's own native HA integration (Mitsubishi Ecodan, Vaillant, Daikin all have community HA integrations of varying quality). The thermostat layer is less important than the heat-pump control layer.

Will my existing dumb TRVs work alongside smart ones? Yes — you can mix smart and dumb TRVs on the same system. The smart TRVs you install dictate the per-room temperature; the dumb TRVs in other rooms keep working as before. Common in practice; nothing to worry about.

What does habbb ship for heating control? We don't ship a thermostat — we integrate whichever one you choose. The habbb kit is the Home Assistant brain (Pi 5 + USB SSD + ZBT-2 + case + PSU); your heating controller is whatever you buy separately and we connect to it.

I'm a British Gas customer with Hive — should I switch to Drayton just for HA? Not unless your Hive is causing you specific problems. The Hive HA integration works well enough for most use cases, and the cost of new Drayton hardware would take 3+ years of energy savings to recoup. Switch if Hive itself is breaking; otherwise, leave it.