With newer models, it could mean that the belt tension has stressed the system. If flapping sounds occur whenever the furnace cycles, it could simply be an object stuck in the air intake. It could be something small enough to get through the vent but large enough to get stuck, like a piece of paper.
Several factors can contribute to a flickering or wavering furnace flame: Airflow Issues: One common cause of flame flickering is turbulent airflow within the furnace. This can be due to a dirty air filter restricting the flow of air, blocked vents, or even the incorrect installation of ductwork.
Loud Bangs, Rumbles, Knocks, or Booms
Loud noises like this are a sign of a build of gas in a furnace. The noise you hear can mean your heat exchanger is at risk of cracking. Even worse, it's a sign that something dangerous could happen if you continue to use your heater.
It's normal for loud banging sounds to originate from ducts as the furnace starts up – it's just the sound of the metal ductwork expanding and popping. This is sometimes called oil canning. When the bang is coming from your gas furnace itself, immediate attention is required.
Thumps and bumping noises, like an unbalanced washing machine, often indicate an unbalanced blower wheel or motor. This is a serious issue that requires immediate HVAC repair. The blower wheel and motor are major furnace parts and you don't want them bouncing around.
If flapping sounds occur whenever the furnace cycles, it could simply be an object stuck in the air intake. It could be something small enough to get through the vent but large enough to get stuck, like a piece of paper. Alternately, it could be something more severe.
Believe it or not, a cracking sound from your heater is normal and nothing to worry about. After a heating cycle, heated metal in your ductwork and your furnace can make a crackling noise as it cools down and turns off.
Gas furnaces rely on a smooth ignition process to kickstart the heating cycle. Clicking noises during ignition could signify issues with the pilot light or electronic ignition system. Solution: Schedule a professional inspection to clean or replace the pilot light, ignition components, or flame sensor.
If your furnace produces a loud humming or buzzing sound, there could be an issue with the motor. There may also be something wrong with the fan. It can be something as simple as a loose screw, loose door, or improperly installed furnace filter.
The radiators in your home are connected by pipes that are controlled by valves. Partially closed radiator valves in a steam system may be trapping condensation in your radiators instead of allowing it to flow back to the boiler (i.e., return), which can cause a banging noise when new hot water enters the radiator.
Clogged burners: If the rattling is coming from the burner compartment, it could be due to clogged burners. This can cause the burners to vibrate and make a rattling noise. Dirty air filter: A dirty air filter can cause the furnace to work harder than it needs to, which can lead to vibrations and rattling.
We're here for the long run. So if you hear a squeal, a new click, grinding, or popping when your furnace is at any point in the heating cycle, it's best to have a tech take a look and catch things early.
Turn your furnace off immediately, and call a technician to inspect it if it starts making a scraping noise. A scraping sound could point to a serious issue with your blower wheel, and it can lead to considerable wear and tear on your system if left unresolved.
Steady Pulsing
The sound can also happen if some components of the HVAC system, such as a fan blade or coil, are loose. Insulate your HVAC system to prevent touching between the walls and refrigerant lines. A professional can also tighten any loose parts in the HVAC system to avoid pulsating noises.
The bang that you hear is the sound of a larger volume of fuel finally igniting, creating a small explosion. This issue is called delayed ignition. If you suspect delayed ignition is producing the banging noise you hear, you'll need to clean your burners to stop the furnace from banging.
The Average Furnace Lifespan
A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.
Shake, Rattle, and Roll: Causes of HVAC Rattling Sounds
Screws securing your condenser or evaporator are subject to vibration. Over time, the vibration can loosen screws, creating a rattling sound. For this problem, the solution is very simple: just tighten.
Tapping in metallurgy is the act of extracting molten metal from a furnace or container. Specifically, it refers to the process of draining or pouring molten metal (often alloys) from a furnace or container.
Chirping
This can mean that your furnace is simply heating up and the noise is normal. However, it could also mean that there is something wrong with the mounting plate or blower motor.
The Short Answer Is: Warning signs of a bad furnace ignitor include the furnace not starting or heating, a noticeable clicking sound without ignition, or frequent short cycling where the furnace turns on and off rapidly. Additionally, if the ignitor appears cracked or discolored, it may need replacement.
Unfortunately, a loud rattling sound coming from the furnace can signal that severe problems are afoot. If your system makes rattling sounds when it's just starting to turn on, it's likely a signal that your furnace's heat exchanger is cracked.
A high-pitched screeching noise may indicate a problem with the motor bearings. If your furnace makes clicking noises when turned on, it can point to an issue in the motor or capacitor.
A good cleaning and calibration should resolve the problem. Bearings keep the blower running smoothly. Just like any other furnace component, however, they can wear out. Dirt, dust, and debris may block the bearings, and when this happens, odd noises are common.