Smarter Heating & Hot Water

Modulating A Rated Boilers with Smart Modulating Thermostats

How modulating thermostats and OpenTherm controls run A rated boilers more efficiently than on/off room thermostats.

Condensing boilers

In Europe, a majority of boilers have modulating thermostats that regulate the boiler flow temperature dependent on the room sensor. In the UK most boilers have on/off style room thermostats. At MyBoiler, modern efficient A rated boilers are installed with these modulating thermostats as a high standard.

Modulating room sensors, as they are known, can increase the efficiency of the boiler much better than on/off style room thermostats. A good analogy would be that standard room thermostats tell the boiler to simply come on and off, versus a room sensor (modulating thermostat) that tells the boiler exactly the temperature it is currently at and also the temperature it needs to achieve. Also to note, whilst new A rated boilers are able to try and predict demand (also known as internal modulation), these are in no way as accurate as a room sensor (modulating thermostat) combined with a compatible boiler. OpenTherm is one such popular standard that enables this more intelligent way of controlling a boiler.

Smart modulating thermostats

Boiler manufacturers commonly now have their own modulating thermostats that are also available as smart thermostats. Vaillant has vSmart, Worcester Bosch has Wave, and so on. There are also independent smart control manufacturers such as Nest (3rd Generation) and Honeywell Evohome that produce OpenTherm compatible modulating controls.

If your boiler has an OpenTherm connection then you can connect an OpenTherm compatible control. Some boilers such as Vaillant and Worcester have their own proprietary connections, for which you either use their own controls or, if they support OpenTherm modules, any OpenTherm control can be connected. An advantage of using a manufacturer’s own controls is that sometimes more information and control of the boiler can be obtained. A disadvantage of using a manufacturer’s own proprietary controls is that you could also be locking yourself into that manufacturer.

For a list of OpenTherm compatible boilers see our OpenTherm capable boilers page.

OpenTherm logo

To see more information about OpenTherm visit opentherm.eu.

Or see what OpenTherm is on our OpenTherm boilers and controls guide.