What is a 750 millivolt heating system?

What is a 750 millivolt heating system?

Millivolt systems are not very common and are primarily used in direct- or top-vent wall furnaces. Millivolt thermostats use very low voltage, usually 750 millivolts (mV) or 0.75 volts. Unlike low-voltage systems, they do not require a step-down transformer and are not connected to the household wiring system.

How does a millivolt system work?

The most common type of gas fireplace uses a millivolt ignition system. The piezo ignitor is usually connected to a button that generates a spark when depressed. The thermocouple generates about 20-30 millivolts, enough electricity to keep the part of the gas valve that controls gas flow to the pilot assembly open.

How do I install a millivolt thermostat?

How do I Wire a Honeywell Millivolt Thermostat?

1. Turn off the electricity to your heating unit, such as a furnace or boiler.
2. Connect one thermostat wire to one screw terminal on your millivolt thermostat’s wall plate.
3. Connect the second thermostat wire to the second screw terminal on your thermostat.

Does ecobee work with millivolt systems?

Unfortunately, the Ecobee (and Nest and most other competitors as well I believe) don’t support millivolt heaters natively. They only support the HVAC wiring system. Millivolt does not contain wiring for power, so that has to be managed as well.

How many wires does a thermostat need?

The most basic thermostat has 2 wires; usually a red and a white wire. Two wire thermostat wiring is used for furnaces only and usually doesn’t need a “C” or “Common” wire. That’s why we only need two wires: Red wire for power (24h).

How does a millivolt gas fireplace work?

How many wires does a millivolt thermostat have?

two thermostat wires
Millivolt heating systems use two thermostat wires for operation. Either wire can be connected to either screw terminal on your Honeywell millivolt thermostat.