Step by step
Old thermostat off the wall. Check the wiring, usually two thin wires to the boiler. New thermostat on, pair with the boiler, install the app, set the schedule. Half an hour, if there are no surprises.
The surprises
Sometimes the old wiring turns out to be broken, or there’s a wireless receiver at the boiler that has to go. Then it takes fifteen minutes longer. The rate stays the same.
OpenTherm or on/off
A boiler with OpenTherm adjusts its output to what the thermostat asks for. Without OpenTherm the boiler fires at full power and then shuts off. That works too, but uses more gas. We'll check which one you have.
