Furnace Pilot Light Thermocouple

In this episode of repair and replace vance shows how to replace the thermocouple.

Furnace pilot light thermocouple.

A thermocouple is a safety device that helps control the gas supply in gas heated furnaces. For a basic test attempt to turn on the pilot light again. Newer gas appliances have igniters that start the pilot light as needed. When it stops working the furnace s pilot light also turns off.

This rod is connected to your furnace s gas valve. When your pilot light is lit the heat from the flame sends a voltage through the thermocouple that keeps the gas line open. This maintains gas flow to the pilot until the thermocouple gets hot enough to open the main gas valve. The function of the thermocouple in your gas furnace is to check to see if the pilot light is on or off.

If the pilot light goes out the thermocouple will lose its voltage and the gas line to your furnace will be closed. Place the lit match or ignited lighter tip at the pilot while depressing and holding the reset button or depressing the knob as appropriate. It is a safety device that shuts off the gas if the pilot light goes out or the electric igniter fails. When the thermocouple detects the pilot light is off it will shut down the gas flow.

It contains a metal rod that is placed very close to your pilot light s flame. If you re having trouble locating the pilot or thermocouple double check to make sure your unit actually has a standing pilot light. Standing pilot lights are common in older furnaces but many newer furnaces have intermittent pilot lights or hot surface igniters. Depress the button or knob for about 30 seconds.

The thermocouple is a gas furnace component located near the pilot light burner. If your furnace pilot light won t stay lit then it might be an easy fix. A thermocouple is a safety device that s used to detect whether or not your furnace s pilot light is lit. The thermocouple detects the pilot light as it can sense the heat the pilot light creates.

This is all done as a safety feature so there are no gas leaks. In these systems the pilot will only light in the case of hot surface igniters the igniter surface heats when the thermostat makes a command for heat. If you re still unsure or don t have a working pilot light test the thermocouple with a multimeter.