A failing furnace might not be immediately obvious, but there are some key indicators to watch for. If you notice any of these signs, don’t panic. Instead, contact a trustworthy HVAC technician to discuss the necessary steps.

Dust: An excessively dusty furnace needs attention. Clean it and keep the surrounding area clean. Dust can clog your furnace’s air filter and duct system and pose a fire hazard, especially if you have a gas-powered furnace.
Age: Older furnaces naturally require more repairs. If your furnace is 15-20 years old, be prepared for more frequent repairs and consider planning for a replacement.
Yellow Pilot Light: A yellow pilot light in your gas furnace can indicate a carbon monoxide leak from the heat exchanger. The pilot light should be mostly blue and steady. If you see a yellow pilot light, contact a professional immediately.
Noises: Furnaces should produce the sound of gently blowing air. Unusual noises like banging, clanging, rattling, or booming are signs that something is wrong and need to be addressed quickly.
Increased Heating Bills: If your heating bills are consistently rising and are higher than your neighbors’, your furnace might be inefficient or malfunctioning.
Cold Air: If your home or business remains cold despite setting a higher temperature on the thermostat, there’s likely an issue with your furnace that needs repair.