There are several noises homeowners hear when their furnace is in operation. A pop or click when turned on and a dull hum when turned off are completely normal. However, what happens when you hear more intense noises? If your furnace is making odd noises, there is a possibility something is wrong.
We understand the level of panic a noisy furnace can cause. These loud and unpleasant noises coming from your furnace could be the result of many factors or causes. Let’s break down the potential reasons for these furnace noises and what you can do about them. This will allow you to put these annoying noises behind you and enjoy an efficient furnace once again.
Common Causes of Strange Furnace Sounds
Hearing strange noises from your furnace is understandably frustrating. You’re also probably wondering why your furnace is making sounds in the first place. Let’s look over some of the common causes of a noisy furnace or heat pump.
1. Damaged Blower Motor
One of the likely causes behind a noisy furnace is a bad blower motor. The blower motor is responsible for pushing warm air out of the furnace and into the air ducts. Since the blower motor has several parts for operation, proper upkeep becomes even more important. A blower motor’s bearings can overheat, experience wear and tear, and simply age out.
What does a bad blower motor sound like? A damaged blower motor can emit several sounds like a high-pitched squeal, rattling, screeching, or even a whistling sound.
2. Dirty Gas Burners
If your furnace’s gas burners become too dirty, they can delay the system’s ignition for gas buildup within the combustion chamber. This occurrence leads to an alarming bang or explosion sound soon after ignition. The best way to prevent this from happening is to make scheduled inspections and cleanings a staple for your furnace.
3. Cracked Heat Exchanger
Another reason your furnace is making noise could be the result of a cracked heat exchanger. Heat exchangers are a thin metal shield between the blower and combustion chamber that prevents gas and combustion fumes from escaping.
While a loose component or panel in the furnace can lead to rattling noises, the persistence of this particular sound could be a sign of a cracked heat exchanger. A cracked heat exchanger should be addressed immediately to avoid carbon monoxide poisoning.
4. Loose Parts
A furnace system has a plethora of moving parts, components, and panels. Did your furnace start making strange noises when you turned it on at the beginning of the winter season? Loud ratting noises can be caused by loose parts in your heating system.
For a properly functioning furnace, all connections and parts must be tightened accordingly. Routine heating maintenance and system checkups allow technicians to tighten components and lubricate moving parts, preventing further issues.
5. Defective Ignition System
A furnace’s ignition system is responsible for creating the combustion needed for producing heat. When the ignition system becomes defective due to a broken sensor, faulty pilot light, or a malfunctioning ignition board, it’s common to hear a clicking sound if it fails to light.
If you notice this clicking sound, make sure to contact AccuTemp immediately so our technicians can fix the issue and get your furnace up and running again.
6. Loose Fan Belt
If your furnace has a belt-driven motor it’s possible that it can become loose and create squealing or screeching noises over time. When this happens, an HVAC technician will have to either adjust the belt or replace it with a new one.
Additionally, other components like shaft bearings can also produce the same noise. This is the result of loose components coming into contact with each other, which can also lead to bigger issues if left unaddressed. Whether it’s a thrown-off fan belt or loose shaft bearing, reach out to an HVAC expert to resolve the issue with precision.
7. Malfunctioning Blower Wheel
Even as a contributing component of the blower motor, an issue with the blower wheel creates a much different sound. If a blower wheel were to come loose, it would cast a large clanking sound as it comes into contact with the blower house casing. If you hear this noise, turn off the furnace to prevent future damages and contact an HVAC official to determine if repairs or heating replacement is the necessary route.
8. Electrical Issues
Maybe you’ve noticed a buzzing or humming noise. A dull hum from your furnace is normal, but if these sounds are especially loud, there could be an electrical issue within the furnace.
Various electrical issues within a furnace that could lead to these noises include:
- Old blower motor
- Faulty inducer motor
- Malfunctioning transformer
- Failing blower motor capacitor
Different Types of Furnace Noises and Issues
Let’s look at the different types of furnace noises and issues and directly pair them with each other. This will give you a better understanding of which type of noise is probably linked with a certain issue.
Scraping Noises
The presence of scraping noises most likely is related to the blower wheel. When the blower wheel is broken it can emit this sound, or when it’s loose it can grind up against the furnace’s other components.
Squealing Noises
Squealing noises are either the cause of issues with the blower motor bearings or the furnace’s belt. This type of noise can most likely be fixed with the tightening and lubrication of the blower motor bearings and an adjustment or replacement of the belt.
Whistling Noises
Whistling noises are also related to the blower motor. A high-pitched whistling sound can develop due to airflow issues with the blower motor and can be fixed by cleaning or replacing the air filter.
Banging Sounds
Banging sounds can be the result of:
- Ductwork issues
- Dirty gas burners
- Delayed ignition
- Cracked heat exchanger
Rattling Noises
If you’re hearing rattling noises, it’s commonly related to a loose panel. Panels, doors, and parts can all become loose over time and can be addressed properly with routine maintenance.
Buzzing Sounds
Buzzing or humming sounds within the furnace are commonly associated with electrical issues. Electrical issues with the fan or motor in your furnace are known to emit these noises and should be addressed by a professional.
Clicking Noises
In the event of clicking noises, the furnace is probably failing to complete its ignition process. Ignition issues can be linked to dirty gas burners, a damaged flame sensor, or a faulty ignition board or valve.
Professional Furnace Repair and Replacement Services
If your furnace is experiencing any of these noises, it’s important to reach out to local HVAC professionals as soon as possible. Our team offers exceptional furnace repair services in New Orleans, Louisiana and will work with you to keep your house warm throughout the cold months.
We also offer a variety of other types of 5-star heating services such as geothermal system installation, heat pump repair, zone control system maintenance, and ductless repair. Give our technicians a call at (225) 244-8826 to receive support with a malfunctioning furnace in your home.
