As a member of Opentherm Association, we are proud of that E-top design thermostat can meet most of the Opentherm protocol boiler. Checked membership on Opentherm website. OT thermostat is different from the traditional ON/OFF type thermostat. OT thermostat can control the boiler better with Opentherm protocol: far away from simple ON/OFF control, control water temperature together with ON/OFF, which can make the boiler working more stable to avoid frequently ON/OFF, protecting boiler and improving boiler efficiency. What’s more, it’s more convenient for end-user to operate: control heating water and living water on thermostat directly. Users can control the thermostat on smart cellphone with WiFi OT thermostats E-top controls provide many models wireless OT thermostats such as: WT-20 & R07, WT-11 & R07, WT-08 & R07. Welcome to visit website for more detailed information, if find any interest, please send inquiry to info@etopcontrols.com, we can provide you excellent OEM/ODM service with our rich experience.