APP: Tuya Smart Life. (APP: Tuya). 1 X Smart Tuya WiFi Thermostat. Function: Plumbing function, gas wall-hung boiler function, electric heating function. Optional: A type: 3A plumbing without WiFi B type: 3A plumbing with WiFi, C type: 16A without WiFi, D type: 16A plumbing with WiFi.