Furnace Thermal Coupler

Natural gas and propane burn cleaner than fuel oil and most gas furnaces present fewer operational difficulties than oil burners do.

Furnace thermal coupler.

This device generates a small electric signal to keep the gas valve open when the pilot is on. If it accumulates soot it can give off a faulty reading and shut off the furnace. The thermocouple is a safety device located by the pilot light on your furnace. Honeywell home cq100a1039 u cq100a1039 replacement thermocouple for gas furnaces boilers and water heaters 30 inch 4 7 out of 5 stars 80 9 31 9.

Honeywell cq100a1013 u not available cq100a1013 24 inch replacement thermocouple for gas furnaces boilers and water heaters quot 4 5 out of 5 stars 191 8 62 8. If the pilot lights but won t stay lit the thermocouple is probably bad. You can test it with a multimeter. Most gas furnaces use either a flame sensor or a thermocouple often referred to as a thermal coupler both are safety devices that sense the presence of a flame and control the flow of gas to the appliance accordingly.

If no flame is present the sensor stops or prevents the flow of gas from the gas valve thus preventing the dangerous situation of gas flowing into the appliance when there.