Worcester Bosch EasyControl review
Worcester Bosch EasyControl Smart Thermostat, Plus 3 ETRVs
By Tom Calder
Key specs
The maker's figures.
- Works with
- Worcester Bosch boilers natively; others need the EasyControl Adapter
- Control
- EMS 2 modulation, not OpenTherm; hot water scheduling included
- Zoning
- Multi-zone: 3 TRVs included, up to 19 TRVs across 20 zones
- Fitting
- Installer-fitted; Worcester points buyers to accredited fitters
If you already own a Worcester Bosch boiler this is a strong package: native EMS 2 modulating control, hot water scheduling, three Smart TRVs in the box, and a system that scales to 19 Smart TRVs across 20 zones on Worcester's own figures, with an up-to-12-year guarantee when installed with one of their boilers. If you do not own one, the maths falls apart — you need the separately sold EasyControl Adapter to convert EMS out to OpenTherm, iRT or a 230V on/off contact, on top of the bundle's own price. Worcester states the EasyControl boosts a system's ErP rating by 5% with at least three Smart TRVs, or 4% without Bosch TRVs; those are its own figures and explicitly conditional on the installation.
- Best for
- Homes that already have a Worcester Bosch boiler and want zoning plus the extended guarantee.
- Skip it if
- Your boiler is not a Worcester Bosch
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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
- Three Smart TRVs included, scaling to 19 TRVs across 20 zones on Worcester's own figures
- Native EMS 2 modulating control on Worcester Bosch boilers, plus hot water scheduling
- Up to a 12-year guarantee when installed with one of Worcester's own boilers
Worth knowing
- Not an OpenTherm device — any non-Worcester boiler needs the separately sold EasyControl Adapter, the biggest hidden cost on this page
- Worcester directs buyers to accredited installers rather than DIY, and the headline guarantee is conditional on how it is installed
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Our review
Worcester Bosch's own smart controller, sold here as the CT200 wall unit with three Smart TRVs, so a Greenstar household can zone rooms from day one. What decides it is the boiler on your wall: on a Worcester it plugs straight into the boiler's EMS bus and modulates; on anything else it needs an adapter first. For Worcester owners who want room-by-room control and an installer is coming anyway.
What it is
The EasyControl is a touchscreen wall thermostat that talks to a Worcester or Bosch boiler over the two-wire EMS bus rather than a simple on/off contact. The bus also powers it, so there are no batteries and no plug: Bosch's manual gives 14.3 to 16 volts DC from the boiler, a maximum draw of 0.9W and a cable run of up to 100m; Worcester also sells an RF Key for a wireless link. Speaking the boiler's own protocol lets it modulate the flame rather than just switch it. The three Smart TRVs in this set fit M30 x 1.5 valve bodies, run on two AA cells that Bosch rates for at least two years, and fall back to frost protection below 4°C.
Zoning and what the app does
Worcester's FAQ puts the ceiling at 19 Smart TRVs split into 20 zones, with the wall unit counting as one. The free app, which Worcester says needs no subscription, carries home presence detection that lowers the heating when the last of up to ten registered phones has left, weather compensation from local internet weather data, hot water timing with comfort, programmed and off settings on a gas boiler, and graphs of gas used for heating and hot water that can be priced at your tariff. Bosch's efficiency claim is narrow: a 5% uplift to the system's ErP label once three or more Smart TRVs are fitted, or 4% without them when weather compensation is on. Those are label figures, not a promise about your bill.
Compatibility and installation
Bosch's manual says heat sources that use iRT, OpenTherm or plain on/off switching can only be connected through the EasyControl adaptor, sold separately. The brochure lists Greenstar i, Si Compact, CDi Compact, CDi Classic and Highflow CDi combis plus 12i to 30i and CDi Classic system boilers, with date caveats; the website carries the current list. On a boiler with the orange controller socket underneath it is a two-wire job; where that socket is hidden, Bosch says the casing must be opened by a recognised installer. Fitted with a replacement Worcester combi in England it covers the Boiler Plus rule that every new combi carries one of four extra efficiency measures; Worcester says it meets three of them.
How it compares
Drayton's Wiser Multi-Zone Kit 1 (2nd gen) includes two radiator thermostats rather than three, grows to 16 rooms and 63 devices on Drayton's figures, and talks to a combi over OpenTherm or relay with no adaptor. The Honeywell evohome pack goes further, to 12 zones and a hot water zone across most boiler types, but ships with no radiator controllers at all and is an engineer's job. The tado X starter kit is the single-zone alternative with hot water control built in. All eight are on our smart thermostat comparison.
Living with it
The wall unit measures 153 by 103 by 24mm, weighs 250g, is rated IP30 and connects to 2.4GHz Wi-Fi, with Zigbee to the valves. Bosch's manuals give a two-year manufacturer's warranty on the EasyControl itself; Worcester's product page advertises up to twelve years when it is installed alongside one of its boilers, which the footnotes tie to a Worcester Accredited Installer and a Greenstar system filter, so ask the installer which applies. Worcester commits to security updates for this set until 31 December 2032. All data stays on the device, and the schedule keeps running without internet, though presence detection needs the app. Worcester's page says smart home integration is coming but lists no Alexa, Google or Matter support today, so check before relying on one.
Our verdict
Buy it if a compatible Greenstar is already on the wall, you have three rooms worth zoning, and an installer is booked, because the guarantee uplift only exists through them. Look elsewhere if your boiler is another brand: once you have added the adaptor and fitting, a Wiser or tado kit does the same job with less friction. For a cold snap on a budget, see staying warm without the heating on.
A researched review, built from the maker's specs, manual and UK listings; facts checked 21 Oct 2026. Sources: Worcester Bosch: Bosch EasyControl product page; Bosch EasyControl operating manual (6720884199, 2024); Bosch EasyControl installation and operating instructions; Bosch Smart TRV installation and operating manual (6720881858); Bosch EasyControl brochure (compatible Greenstar boilers, ErP claims); Worcester Bosch FAQ: how many Smart TRVs can I connect?; Worcester Bosch FAQ: does a power cut affect EasyControl?; Worcester Bosch FAQ: security update period; BEIS: Boiler Plus factsheet (April 2018 standards, England).
Who shouldn't buy this
Don't buy it if your boiler is not a Worcester Bosch — Drayton's Wiser Multi-Zone kits give comparable zoning and need no adapter.
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 4 Nov 2026, 19:07 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 An S-plan or Y-plan home with a hot water cylinder that needs one thermostat to run both.
Read the review →
Best for Room-by-room control on a combi boiler without paying whole-house-system money.
as of 4 Nov 2026, 19:07 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
Does the Worcester Bosch EasyControl work with a non-Worcester boiler?
Only through the separately sold EasyControl adaptor, which Bosch's manual says is required for boilers that use OpenTherm, iRT or on/off switching. Worcester's advice is to ask a local installer whether your model is supported before buying.
Can the EasyControl control hot water?
Yes. Worcester says you choose the hours the boiler provides hot water in the app, and on a gas boiler the manual offers comfort, programmed and off settings.
How many Smart TRVs can the EasyControl run?
Worcester's FAQ says 19 Smart TRVs across 20 zones, the wall unit being the twentieth, This set starts you with three.
What happens to the EasyControl in a power cut?
Worcester says the controller loses power with the boiler and the heating stops, but it keeps your settings; when the supply returns it reboots, picks up the time online and resumes the schedule. If the boiler itself stays off, see boiler not working after a power cut.
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