I have an OpenTherm Combi boiler can I use it with Wiser?

Yes, you can If you have a Wiser Thermostat Kit 1 and an OpenTherm enabled combi boiler. Wiser comes with a Communication Module located to the rear of your Wiser HubR and needs to be wired up to start using the OpenTherm capability. Where wiring is concerned we would always advise that you seek the aid of a qualified installer / heating engineer.