Why is My Furnace Making a Clicking Noise?Furnaces aren’t meant to be noisy; they should run quietly in the background. A furnace making a clicking noise is malfunctioning and the problem will likely grow worse over time. Though it requires an HVAC contractor to properly diagnose and repair the issues, the most likely causes are:

Loud Circuit Board

Circuit control boards act like a relay station, passing messages between different parts of your furnace. Each one contains a series of switches that flip on and off, activating and deactivating various components as needed to keep warm air flowing through your home. These switches are designed to operate silently, but in some cases they can be too loud. Replacing the circuit board will solve the problem, although if the rest of the furnace is running smoothly, some homeowners decide to live with the problem instead.

Worn Out Bearings

Ball bearings reduce rotational friction in furnace fans. However, the constant pressure gradually wears them down. Unless replaced, the fan assembly will eventually become unstable and start to click. While an unstable fan will function for a while, it will continue to deteriorate until it fails completely.

Dirty or Damaged Fan

Gas and oil furnaces contain two fans: a blower and an inducer. The blower circulates warm air throughout your house. The inducer collects exhaust and vents it out your home. Dirty blades can throw one or both of these fans off balance and create a clicking noise. Chipped or broken blades have the same effect.

Bad Igniter

In a gas furnace, there’s a clicking noise before the igniter activates the burners. The same thing happens on a gas stovetop as current flows into the igniter and begins sparking. Igniters are supposed to shut off once the burners are lit, but if their electrical components have worn out or have a bad connection to the flame detector, they may spark continually.

Bad Flame Detector

Igniters are controlled by the gas valve and flame detector, also known as the thermocouple, which cuts power to the igniter once the burners begin producing flames. A dirty or malfunctioning detector might not register the flames or signal the igniter. If this is the case, the igniter will keep sparking until it wears out. Cleaning or replacing the detector is the only way to solve the problem.

Broken Gas Valve

Gas valves supply burners with fuel. They’re supposed to activate at the same time as the igniter, to create a controlled flame. This means that if they don’t open, the igniter will continue sparking endlessly, waiting for a signal from the flame detector that the burner has been lit. Broken gas valves are one of the easiest problems to detect, since the clicking noise won’t be accompanied by any hot air.

Faulty Pilot Light

Older furnaces use a pilot light rather than an ignition switch, but they operate on similar principles. As gas flows into the unit, it hits the pilot and ignites the burners. But if the pilot light is dirty or isn’t receiving the right mix of gas and air, it won’t produce a flame strong enough to ignite the burners. When this happens, the furnace will automatically shut off and restart ‒ a safety feature that prevents gas from leaking into your home. While this constant cycling isn’t dangerous, it creates a lot of noise.

Poor Ductwork

Loose ducts rattle and click as air circulates. Though they may sound similar to a malfunctioning furnace, there is one distinct difference. While a noisy furnace is irritating, its sounds are confined to one part of your house, generally the basement or attic. Noisy ducts, on the other hand, can be heard all over your home.

Protect Your Heating System with Agway

Unfortunately, a furnace making a clicking noise isn’t covered by home insurance because damaged fans, faulty igniters, and worn bearings are caused by wear and tear, not accident or disaster. In these cases, the homeowner has to shoulder the cost of repair by themselves. But not if they’ve signed up for Agway’s EnergyGuardTM Program.

EnergyGuardTM protects your heating, cooling, and electrical systems* against damage resulting from repeated use. When the need for repair occurs, our customers don’t have to scramble to find a qualified repairman. They call us instead. We maintain an extensive network of contractors and will send the first available one straight to your home. There are no service fees or deductibles. We pay for the cost of the visit, as well as all covered parts. Sign up and start enjoying the benefits of EnergyGuardTM today!

*Coverage depends on which commodity you purchase.