A gas furnace is one of the most reliable sources for heating a home through the winter. The gas-powered burners generate high amounts of heat, and the blower fan can send the heat quickly around the rooms of the house for excellent comfort.
But then there are those times when a furnace doesn’t quite do what it’s supposed to! When you adjust the thermostat to bring heat to your house, and the furnace’s burners don’t ignite, you won’t have warmth anywhere in the house unless you’ve got a fire in the fireplace.
Burners that won’t light are a problem we often see when we’re out providing gas furnace services in Salt Lake City, UT, and we know all the causes. Below are reasons you may have burners that won’t burn.
The pilot light is out
If you have a gas furnace that was made more than 15 years ago, it may use a standing pilot light to ignite the burners. This is a well-known type of gas furnace: if you can look into the cabinet and see a single burning blue flame at all times, the furnace has a standing pilot light. If the pilot light goes out, for any reason, the burners won’t come on. You can relight the burner with a match or grill lighter. If it won’t stay on, the pilot light assembly may be dirty, or you’ve lost natural gas flow. Call for professionals to repair the system. (And may we strongly recommend installing a new furnace without a standing pilot light? They’re more dependable and use less energy.)
Broken electronic ignition system
Modern gas furnaces have replaced the old pilot light with electronic ignition systems. Hot surface igniters burn filaments, like lightbulbs, to light the burners, and intermittent pilot lights use an electric spark to light a pilot light only as needed. The electronic igniter could also fail—similar to a lightbulb burning out—but it’s easy to have HVAC experts put in a new igniter when this happens.
Gas line issues
The burners may not be lighting because no natural gas is reaching them. Check to see if the gas valve is turned so it’s open. If this doesn’t fix the problem, please don’t try any more work on your own. It’s time to call professionals, since only a licensed expert is permitted to work on a natural gas appliance.
Dirt along the burners
The burners themselves may be clogged up with grime or rust, and this is stopping them from drawing enough air to ignite. As with other furnace repair jobs, let the experts handle this, since they must detach the burner itself in order to properly clean it.
Furnace limit switch trouble
A gas furnace has a special safety limit switch to shut off the burners in case of overheating in the combustion chamber. An HVAC expert must see why the furnace is overheating to ensure it continues to run safely.