Skip to content
sumcraft

solutionssmart thermostat

Baxi Boilers and Smart Thermostats: Nest, Hive, tado and OpenTherm

Yes. Hive, Nest and tado work with most Baxi boilers. Baxi says its current Combi 2 and System 2 boilers are fully compatible with OpenTherm. Here is what each maker documents, and how the wiring differs.

Sumcraft Editorial Team7 min read

Aa

Yes. Hive, Nest and tado work with most Baxi boilers, and Baxi says its current Combi 2 and System 2 models are fully compatible with OpenTherm.

Checked on 1 November 2026. Everything below comes from the boiler and thermostat makers' own documents. They are linked at the end. We have not installed these thermostats ourselves. Have a qualified heating engineer wire any thermostat to your boiler.

ThermostatWhat the maker documentsOn a current Baxi
HiveWorks with most boilers. No Baxi model on its incompatible listOn/off. Hive sells V4 OpenTherm models
Google Nest (Thermostat E, 3rd gen Learning)OpenTherm or on/off wiringOpenTherm on Combi 2 and System 2 models
tado XWorks with boilers that have a relay or OpenTherm connectionOpenTherm or on/off
Baxi uSense 2Baxi's own smart thermostat. A two-wire, low-voltage connection with load compensationCombi 2 models only

Two ways a thermostat connects to a Baxi boiler

  • On/off (230V). The thermostat switches the boiler on and off. The boiler then runs at the temperature set on its own dial.
  • OpenTherm (low voltage). The thermostat tells the boiler what water temperature to run at. Baxi says its OpenTherm boilers "can maximise efficiency when fitted to OpenTherm Certified controls".

Baxi's installation manual for its Combi 224 to 428 range shows both connections. Terminal X4 is for a 230V "Room thermostat/timer". Terminal X8 is the "On-Off/R-Bus" room thermostat connection. Baxi says its jumper "must be REMOVED to connect a device".

The same manual says "Any proprietary OpenTherm control MUST allow individual adjustment of CH and DHW temperature". That means separate control of heating and hot water temperatures. Terminal names can differ on other models, so your engineer should check your boiler's own manual.

Which Baxi boilers support OpenTherm?

Baxi's 2024 range guide calls these "Fully compatible with OpenTherm":

  • Baxi 400 Combi 2.1
  • Baxi 600 Combi 2 and 600 System 2
  • Baxi 800 Combi 2 and 800 System 2

The guide does not mention OpenTherm for the 400, 600 and 800 Heat (regular) boilers. For an older Baxi, ask Baxi with your model name. Our guide Is my boiler OpenTherm? covers how to check any boiler.

Hive with a Baxi boiler

Hive says "In most cases, our Hive thermostats will work just fine with your boiler". Its list of exceptions names solid fuel boilers and ten older Worcester Bosch models. No Baxi model is on it.

Hive's compatibility page does not mention OpenTherm. Its standard thermostats switch the boiler on and off. UK retailers list a Hive V4 OpenTherm thermostat for boilers that support it.

Nest with a Baxi boiler

Google says the Nest Thermostat E and the 3rd gen Nest Learning Thermostat support OpenTherm. Google's Heat Link guide names the OpenTherm wires OT1 and OT2. On a Baxi Combi 2 or System 2, that lets Nest set the boiler's water temperature.

Is Nest being phased out? In May 2025, Google said "we'll no longer launch new Nest thermostats in Europe". Which? reported that the 3rd gen Learning Thermostat and Thermostat E would stay on sale while supplies last. Which? also said both "will continue to receive security updates". The older 1st and 2nd gen Learning Thermostats stopped getting updates from 25 October 2025.

tado with a Baxi boiler

tado's compatibility page names Baxi among the boiler brands it works with. tado says it works with almost all boilers that support relay connections. It says tado X works with boilers that have a relay or OpenTherm connection. On a Baxi Combi 2 or System 2, either connection should be available. Ask tado about your exact model before you buy.

Baxi's own controls

ControlWhat Baxi documents
Baxi uSense 2"Simple 2 wire low voltage connection enabling load compensation". Baxi's February 2026 guide lists it for the Assure 500, 600 and 800 Combi 2
Baxi RF Thermostat (Twin Channel)Listed for the 600 and 800 System 2 and Heat boilers
Baxi OpenTherm Thermostat (Single Channel)Controls one heating zone, or up to six with extra Baxi thermostats

Baxi's February 2026 guide marks uSense 2 as not compatible with its System 2 and Heat boilers.

Quick answers

Does Hive work with a Baxi boiler?

  • Yes, on most models. Hive says its thermostats work with most boilers, and no Baxi model is on its incompatible list.

Does Hive work with a Baxi combi boiler?

  • Yes. Standard Hive thermostats switch a Baxi combi on and off. A Hive V4 OpenTherm model can use OpenTherm on a Combi 2.

Can I use a Nest thermostat with a Baxi boiler?

  • Yes. Google documents OpenTherm and on/off wiring for Nest. Baxi says its Combi 2 and System 2 boilers support OpenTherm.

What thermostat is compatible with a Baxi boiler?

  • Baxi's own uSense 2 suits its Combi 2 boilers. Hive, Nest and tado also work with most Baxi models.

How do I connect a thermostat to a Baxi boiler?

  • Through the boiler's 230V room thermostat terminal for on/off control, or its low-voltage terminal for OpenTherm. Use a qualified heating engineer.

Is the Nest thermostat being phased out?

  • Google will not launch new Nest thermostats in Europe. Which? reported that the 3rd gen and Thermostat E stay on sale while supplies last and keep getting security updates.

Which boilers are not compatible with Hive?

  • Hive lists solid fuel boilers and ten older Worcester Bosch models. Our Worcester guide lists them by GC number.

Sources, checked 1 November 2026:

  • Smart thermostat
  • Baxi
  • OpenTherm
  • Boilers
  • Home heating

related.