When you turn on the furnace at the start of the cold season, the last thing you want to hear is a clicking sound. During operation, all heating systems make may some type of noise. For example, a radiator might make a slight hissing sound, a ductless system might hum a bit, and even a furnace might rumble slightly when powering on or resetting a cycle. However, repetitive clicking sounds can indicate a system failure or malfunction. The most common causes of a clicking furnace include ignition system problems and internal part damage. A look at the top causes can keep you informed on when it is time to contact an HVAC professional.

Faulty Ignition System

A faulty ignition system is one of the main reasons that your furnace might start clicking. Just as a car ignition makes a grinding noise in the event of ignition failure, a furnace ignition makes a clicking sound to indicate malfunction. When you set your thermostat to heat up the household, the furnace works by using its fan motor to draw air into the burner. The job of the ignition system is to build up enough energy so that when the gas valve opens to mix gas with air, it can create a spark that lights or ignites your burner. As a result, the burner can produce heat that the furnace’s blower can then distribute throughout your rooms. If any step in this process fails, you can start to hear clicking sounds. Specific culprits behind ignition problems include a failing flame sensor, a damaged pilot light, or a blocked gas valve.

Failing Flame Sensor

The flame sensor or thermocouple detects the presence or absence of a burner flame. This device sends a signal to the valve on whether it is time to open or shut accordingly. If the flame sensor is dirty or clogged, however, it will be unable to send this signal. You may then hear a clicking sound from the igniter instead. An HVAC professional can check for clogging, corrosion, or other problems with the flame sensor.

Damaged Pilot Light

The pilot light is an ignition source for your burner. Any incorrect mixture of gas and air will render the pilot light unable to reach the flame sensor. This can cause the pilot light to attempt to ignite repeatedly, resulting in the dreaded clicking sound.

Blocked Gas Valve

A blocked or jammed gas valve may fail to open and release gas. When this happens, you may hear the ignition system click endlessly. The sound is reminiscent of a gas stove burner that clicks instead of igniting or a manual light that will not spark a flame. In addition, faulty gas valves can cause too much fuel to build up in your system and make your furnace more vulnerable to a gas leak. It is important to contact a professional right away if you suspect gas valve issues.

Loose or Broken Interior Parts

A furnace can also make clicking noises if interior components are torn, broken, or loose. Common interior parts that may break down include the fan, electrical elements, blower, or ductwork.

Worn Fan or Inducer

The furnace fan has several functions. It draws air into the burner at the start of each heating cycle, it fuels the burners with consistent oxygen, and it clears away leftover gas once the cycle is complete. With such heavy usage, the fan’s blades can wear out over time. The blades can also break down due to dirt and debris. Both instances can cause clicking sounds. An HVAC professional can clean, calibrate, or repair the fan to resolve the problem.

Damaged Electrical Components

Electric furnaces use electrical elements in their starter system. These elements or wires can wear out over time. If you hear clicking sounds from your electric furnace, it is time to contact a professional to make repairs.

Blocked Blower Bearings

Bearings help keep the blower operating smoothly. Within a furnace, bearings work to minimize friction and reduce noise pollution. Unfortunately, dust or debris can block these bearings. This blockage results in a clicking sound. An HVAC professional can check to see if bearings are dirty and need to be cleaned or lubricated. If the problem is more extensive and involves rust or corrosion, the HVAC technician can also provide information on replacements as needed.

Loose or Cracked Ducts

Ducts circulate heated air throughout the home. Any cracks within the ductwork can result in clicking or popping sounds. If your furnace seems to work like normal but you hear clicking from the vents, it is time to contact a professional to check or holes or cracks in your ductwork or duct seams. It is important to handle this problem quickly before heated air seeps from the ductwork and results in higher energy bills.

Get Help Today

While clicking sounds may seem alarming, the situation is not hopeless. OnTIME Service provides furnace help for homes in Henderson and the surrounding tri-state area. We provide furnace installation, inspection, and repair. Our technicians can also answer questions about heat pumps, duct cleaning, and indoor air quality. Contact OnTIME Service for your heating and furnace needs.

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