If your furnace is making a clicking noise, this is a sign of an issue occurring during the heating cycle. When you hear clicking from your furnace, you should contact an HVAC professional immediately, as this strange sound may indicate a faulty igniter or gas valve. Issues with these parts can result in a gas leak.
Understanding Furnace Sounds
With some heating appliances, you simply grow used to the noise. There are hums, whooshes, clicks, and even gentle hisses — it’s the kind of ambience you become comfortable around. Noises like these can be typical of heating systems like furnaces, but you should be concerned when the furnace noise escalates to loud rattling, banging, popping, grinding, and high-pitched whistling noises. If the furnace won’t ignite and emits the smell of gas, you should clear the house and contact a professional to inspect it.
Clicking is a normal part of a furnace’s operation. It’s part of the ignition process or the sound of electrical relays switching. However, if you hear a constant clicking noise, that is usually a sign of a bigger issue.
If you hear a continuous furnace clicking noise, you may think your furnace sounds like it’s trying to start. However, if it fails to light and the clicking continues, then a faulty ignitor or gas valve could be the cause, but those aren’t the only possible sources.
Top 6 Reasons Your Furnace Is Making a Clicking Noise
Let’s dive deeper into some reasons why your furnace is making a clicking noise, along with how to discern one issue from another. Just about all of these issues require the assistance of a trained technician, as they can either be dangerous or difficult fixes to make on your own.
1. Defective Electric Igniter
Most new furnaces use some kind of electronic ignition, honing electricity and gas to heat your home. Whenever you start a furnace with an electric igniter, electricity is used to ignite the flowing gas, but the igniter can be worn out over time.
A worn-out igniter can periodically fail, and if it keeps trying to light the gas, your furnace will make a clicking sound. The noise may last until the flame ignites or the gas valve closes. This failure and its corresponding clicking noise can also result from the igniter’s wiring coming undone. Dirt on the burner or ignitor can also cause the furnace to have a small, cool flame because there isn’t enough gas getting to it, which will cause the igniter to make further clicking sounds.
2. Faulty or Dirty Flame Sensor
A flame sensor detects whether the gas inside your furnace is lit. If the gas is lit, the sensor tells the gas valve to open. The sensor should then signal the igniter to make a spark. When the gas ignites, but the sensor doesn’t detect the flame, the igniter will unsuccessfully try to make a spark, resulting in clicking noises.
The gas valve will automatically close, and the furnace will shut off if the flame isn’t detected. If your furnace isn’t regularly maintained and cleaned, dirt and other debris may begin to cover its flame sensor. When covered, the sensor becomes oblivious to heat. Thankfully, this is a relatively easy issue to avoid. If your furnace is professionally inspected each year, as is recommended, you won’t need to worry about a dirty flame sensor.
3. Gas Supply Problems
If your gas supply is interrupted, clicking noises are a common side effect. You may experience gas supply issues if your gas line becomes clogged or if the main gas supply entirely cuts out. A defective gas valve can also lead to gas supply problems. If there is no gas flow when you start your furnace, the igniter will make a clicking noise until you shut off your heat.
If your furnace refuses to start, be sure to listen for the flow of gas. If you don’t hear anything, try starting your water heater. If your water heater starts, you will want to have your furnace and its gas supply professionally inspected. If your water heater does not work, there could be a larger issue with your gas, and you should contact a certified professional immediately.
4. Malfunctioning Start Capacitor
A start capacitor supplies the energy needed for the fan in your furnace to start. When a start capacitor becomes too fatigued, it can’t supply enough energy to start the fan and instead makes a clicking sound. If you have an electric furnace, then there is no danger of a gas leak, and the clicking may be caused by other electrical components, including the start capacitor, that need repair or replacement.
When a furnace starts making a clicking noise due to a defective start capacitor, the issue is a straightforward fix for a skilled professional. To avoid a gas leak or other issues, do not attempt to fix this component in your heating system without a licensed HVAC technician.
5. Old Fan Bearings
Bearings are essential components of a furnace’s direct-drive motor, which uses those bearings to help the blower fan spin. If bearings become worn out, the fan usually hums loudly while attempting to start.
The first sign of deteriorating bearings will be a clicking or squealing noise sourced from the fan. If your fan bearings are fully worn out or are in the process of wearing out, a technician will need to replace them. It is important to fix bearings, as broken bearings can cause further damage to the blower motor itself, leading to higher replacement costs.
6. Damaged Fan Blades
If your HVAC system isn’t regularly maintained, debris can make fan blades grind against other nearby parts, eventually causing the blades to break off. A broken fan blade will likely make a racket while the fan is running.
When to Call a Professional
Before you call a professional, ensure that the clicking is coming from your furnace. If you hear the noise in different parts of the house or away from your furnace, it may be because of a bearing or part that’s come loose in your ducting system. You should still call a professional to help you, but if it’s not coming from your furnace, it’s less of a critical issue.
However, if the clicking is coming from your furnace, it’s best to always call a professional to handle it. Furnaces can be dangerous if you don’t treat problems promptly.
Professional Furnace Repair and Replacement Services in Southeast Michigan
If you live in Metro Detroit, you understand the importance of having a working furnace during the winter months in Michigan. A broken furnace puts you at the mercy of 10 and 20-degree days, so if your furnace is making a clicking sound, it is important to contact the HVAC professionals at Randazzo Heating, Cooling, and Electrical as soon as possible.
Our professionals offer reputable HVAC services in Sterling Heights, Michigan and other areas. We offer all sorts of services, from yearly furnace maintenance to emergency furnace repairs, and as top-rated experts in the industry, we offer free estimates, personalized service, excellent financing options, and regular promotions.
Regardless of whether you need routine furnace maintenance or a full furnace installation, we will be there for you. Don’t hold off: contact our team online or dial 586-271-8003 to make sure your family stays warm this winter.
Last Updated on March 11, 2025 at 10:00AM EST
