Millivolt Thermostat Systems

The usage of millivolt thermostat systems is very rare. These systems run on very low voltage such as 750 mV (millivolts) and do not need a step down transformer, instead they require a special millivolt thermostat, which cannot be substituded for any low voltage thermostat. A quick way to spot a millivolt system is it does not connect to any AC power, instead it connects to the millivolt thermostat with only two wires.

Operation of a Millivolt Thermostat System

They are powered by a device called a thermopile generator, which produces a very direct current. The thermopile generator is not very expensive and can be easy to install with a push-in ciip. Generally speaking, millivolt thermostat systems are very simple and produce heat only.

Uses of a Millivolt Thermostat System

  • Millivolt thermostat systems are perfect for top vent wall furnaces or direct furnaces. The low voltage systems are more energy efficient, minimize heat and energy loss and can reduce cost.

  • Millivolt thermostat system are often used for gas water heaters. The released energy helps keep the water warm. Another advantage is that there is no need to connect an electrical circuit to the hot water heater if this type of system is used.