Why Does Your Furnace Won’t Stay Lit?

In cold, chilly weather, a well-lit furnace is essential. Also, the furnace must maintain a correct temperature during such weather. If your furnace burner won’t stay lit, there are some possible explanations as to why this might happen.

Even though you should not attempt a broken furnace repair in Salt Lake City on your own, it is still beneficial to understand the potential reasons for the issue.

Common Reasons Why the Furnace Burner Won't Stay Lit

Dirty Flame Sensor

The flame sensor rod in your furnace may be dusty if you observe that it repeatedly turns on. When your furnace’s flame sensor does not detect the presence of a flame, the gas valve will shut off automatically.

A flame sensor that instructs the gas valve to shut off when there is no trace of a flame is an efficient safety feature that prevents the intake of harmful gas. In contrast, an issue that demands immediate care is a soot-covered flame sensor. Call Jones Heating and Air Conditioning for heater installation in Salt Lake City if you notice this issue.

Faulty Flame Sensor

In a gas furnace, the flame sensor is an added safety measure that verifies if the gas produced by the burners has been lit. The gas supply automatically switches off if the flame sensor detects no activity. It will prevent unburned gas from entering the combustion chamber and creating a potentially hazardous condition.

If the flame sensor fails to operate properly, it will falsely determine that the burners have not been started and will shut off the gas supply, extinguishing the burners. The flame sensor only has to be cleaned but may require replacement.

Absence of Combustion Air

Every furnace requires a precise quantity of combustion air to ensure that the flames can breathe properly. There is a way that requires both the total BTUs and the square footage of the area that the gas appliances serve. The furnace can malfunction if the room is too small.

You can resolve this by opening the door to the furnace room or adding vents within the room to let in additional air. The issue is that even when the ventilation system is turned off, unconditioned air enters the home.

However, there are numerous sorts of damper systems that can eliminate this problem. A condensing furnace with two PVC pipes leading to the exterior should be fine during typical operation.

Damaged Thermocouple

To obtain an accurate reading of the flame’s temperature, a safety device known as a thermocouple employs two unique metal wire types. As a result, it will be able to regulate the gas supply to the burner. If the thermocouple judges that the flame’s temperature is insufficient, the gas supply will shut off.

It will prevent your home from filling with combustible gas. If the thermocouple fails to perform properly, it can mistakenly shut off the gas, causing your furnace’s flame to go out.


In some cases you can fix a furnace lighter issue on your own. However, there are times you need to contact an HVAC specialist for heating repair in Salt Lake City. Reach out to Jones Heating and Air Conditioning if you find any issues with your furnace or heater. Our specialists will fix your issues quickly and efficiently.