BoilerBuying Guide2026-02-24
OpenTherm Explained: Smarter Boiler Control
OpenTherm lets the thermostat and boiler communicate so it modulates instead of cycling.
OpenTherm is the key to getting real savings from a modulating combi boiler.
What it does
OpenTherm is a two-way protocol that lets the thermostat tell the boiler exactly how much output to produce, so it modulates smoothly.
Why it saves
Modulating and running longer at lower temperatures beats simple on/off control, keeping the boiler efficient and comfortable.
Key takeaways
- Two-way thermostat-boiler control
- Enables true modulation
- More efficient than on/off
- Check boiler compatibility
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