How to replace an existing TRV head with the Wiser Radiator Thermostat Follow Radiator Thermostat installation tips Related articles How to install your Wiser Radiator Thermostat Replacing the batteries in my Wiser Radiator Thermostat How do I fully close the Wiser Radiator Thermostat so that I can drain down the radiator to take it off the wall without draining the whole system? Wiser Installation Guide Wiser Radiator Thermostats vs TRVs - the differences explained