Troubleshooting Furnace Burner Issues

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A failed burner in a gas furnace means you won't be able to properly heat your home. Knowing the cause can help you schedule the right repair.

Signs of Burner Problems

A problem with the burner often means that your furnace won't produce sufficient heat, if any heat at all. This is because the burner is where combustion occurs. If the burner is malfunctioning, there is no combustion to produce the required heat. Often, the fan will also stop working because most furnace fans only switch on when the temperature sensor detects heated air.

If the furnace burner is igniting but beginning to fail, you may have heat but there may also be an increase in noise from the furnace right as it begins to come on. Usually this noise is a rumble, but there may be a few bangs and pops as well. This is due to poor combustion. Not all of the fuel is combusting immediately, so it builds up and then the excess fuel finally ignites with a bang and a rumble.

Causes of a Faulty Burner

Dirt is often the cause of burner issues. If there is dirt on the burner itself or clogging the fuel valve or igniter, then the fuel may not be delivered properly or it may fail to ignite. Damage to the burner assembly, including the plate, fuel valve, and igniter, may also cause ignition failure. When damage is present, often ignition fails completely.

Another common cause of a faulty burner is lack of airflow. If any of the air coming into the burner is blocked, perhaps due to a dirty air filter or issues with the intake vents, then the fuel will collect but it won't combust on the burner plate. There will likely be a rumble and possibly a bang when it does finally combust. If combustion isn't possible, then gas fumes may leak out of the furnace.

Repairs and Solutions

The most likely repair will be a thorough cleaning of the burner, fuel valve, and igniter. Your service tech will also need to check all of these components for damage and replace any that are no longer able to work properly.

Your burner may also need to be adjusted to allow more air flow into the chamber. If there are blockages, the vents or air filter may also require cleaning or replacement. In the future, changing the air filter monthly may prevent the issue from happening again.

Contact a residential heating service for more help with your gas furnace.