What is a 750 millivolt thermostat?

What is a 750 millivolt thermostat?

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 do you adjust the heat anticipator on a thermostat?


  1. Examine the Thermostat. Remove the thermostat cover.
  2. Locate the Heat Anticipator. Look for the small disc with calibration marks located at the center of the thermostat.
  3. Adjust the Heat Anticipator.
  4. Test the Thermostat.

Why is my new Honeywell thermostat not working?

There are a number of reasons why your Honeywell thermostat may not be turning on. For example, your thermostat may need new batteries. Or, there could be an issue with the wires inside the thermostat. The thermostat may also be confused, in which case it may require a factory reset.

Do you need a special thermostat for gas fireplace?

If you’re thinking of installing a thermostat for your gas fireplace, you may be wondering if you need a special type. We’ve done the research to give you an answer. No, gas fireplaces are very versatile and can be used with any type of thermostat, switch, or remote control.

How do you wire 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.

What should my anticipator be set at?

We also explain the difference between the job of the thermostat heat anticipator and the differential settings on a heating system aquastat or similar control….

Table of General Heat Anticipator Settings
Heating System Type Heat Anticipator Setting Amps
Warm Air, High Efficiency 0.8 A
Warm air, Standard 0.4 A

Why is it important to properly set the heat anticipator?

The heat anticipator in the thermostat prevents the temperature in the conditioned space from rising above the thermostat setting. The cold anticipator starts the cooling system early to allow the air conditioning system to get up to capacity when needed.

How many wires are in a millivolt thermostat?

Millivolt heating systems use two thermostat wires for operation.

Does Nest Thermostat work with millivolt?

The Nest is not like a thermostat that typically uses internal relays to switch on/off the call for heat/cooling and thus don’t really care what the voltage being switched is. The Nest is all solid state, so likely will not work to switch a millivolt relay.

Does Nest thermostat work with millivolt?

Does Nest thermostat work on millivolt system?

What happens if an anticipator is set too low?

Watch out: if you set the heat anticipator too low that causes too much current to flow through the heating coil and will creat too much heat inside the thermostat, shutting the system down too early – before the living space actually comes up to temperature.