A volt-free boiler thermostat, also known as voltage-free boiler thermostat or dry contact boiler thermostat, offers a flexible and safe solution for smart home heating systems.  This fundamental difference brings several advantages. 1. No voltage supplied by thermostat. One of the key benefits of no voltage output. Since the thermostat output terminals do not pass voltage, the risk of damage to the boiler control board due to voltage incompatibility is reduced. And since gas boilers are often installed in humid environments such as basements, the thermostat's voltage-free output design also provides additional safety. 2. Compatibility and flexibility. Because the thermostat contacts are dry contact, they can be used with a wide range of heating control systems and smart home integration and retrofitting heating thermostat. 3. Electrical isolation. Volt free contacts electrically isolate thermostat from boiler’s power supply, which can improve safe heating control and reduce electrical interference or noise affecting the thermostat operation. 4. Simplified wiring and installation. Volt free thermostats typically require fewer wiring considerations related voltage matching. Unlike conventional thermostats that send voltage to operate the boiler, volt-free digital thermostats function purely as a switch—opening or closing the circuit without supplying -any voltage. This design helps simplify both installation and fault diagnosis.