Opentherm Boilers & Controls | Compatibility Guide
How to use this guide
Overview of Opentherm
Most new boilers are ‘modulating’, i.e. they can adjust the amount of gas they use between a set range of outputs, for example between 5kW and 18kW. This makes them very efficient as they can reduce their output during warmer periods.
Both weather and load compensation thermostats are designed to work with modulating boilers and tell them what kW output they should be operating at. The thermostat and boiler need to speak the same ‘language’. In technical terms this is referred to its ‘communication protocol’.
Most manufacturers use a unique language for their own boilers and controls. This means that the number of compensation control brands that will work with a specific boiler is limited. A recent study from the BRE (Evidence Gathering – Compensation and TPI Heating Controls) reported that of 28 compensating heating controls reviewed, 74% used manufacturer specific communication protocols and only 26% used Opentherm.
Opentherm is available to for any boiler or heating control manufacturer to use and means that different brands are compatible with each other. We guide you on which brands use the Opentherm language below.
New Boiler Plus requirements
A new combi boiler must have an ‘advanced feature’ i.e. weather compensation, load compensation or automation & optimisation functions. The new regulations differ however for heat only and system boilers and existing installations, as follows:
New installations of a combi boiler:
require a programmable room thermostat with an ‘advanced’ energy saving feature, i.e weather compensation, load compensation or smart controls that combine automation and optimisation features. For compensation controls, they must speak the same language.
New installations of a heat only or system boiler:
require a programmable room thermostat or a thermostat with separate programmer. You can still opt to install an advanced control and we guide you compatibility below.
Existing boiler installations:
have no minimum requirement for heating controls. You can replace your room thermostat with another room thermostat and nothing more. Again you can opt for an advanced control or may wish to have the functionality of an internet control and we guide you suitable products below.