Why does my furnace make a whining sound when I start it?

Author: Stan Rosenbaum  |  Last update: Friday, February 6, 2026

If the blower wheel or motor mount has broken, it will need replacement. A HIGH-PITCHED WHINING NOISE could be shaft bearings that need oil, or it could be a loose, slipping or frayed blower belt, which will need to be adjusted or replaced. Worst case scenario, the blower motor may need replacement.

Why does my furnace whine when I start it?

The Blower Motor Bearings or Wheel May Be Bad

A bad blower wheel can cause the loud, high-pitched sound you're hearing. The good news is it's an easy fix if this is the problem. You can replace it yourself or call a technician to come out and do it for you. A bad motor can also cause an annoying noise.

Why does my furnace make a weird sound when I turn it on?

If your furnace is making a loud banging or booming noise when it turns on, the two most common causes are: Problem with the ignition system. Expansion and contraction of metal ductwork.

Why is my blower motor making a whining sound?

High-pitched whining and squealing can indicate the bearings in your furnace's blower motor are worn out. Bearings can have a long lifespan–up to 30 years–with the proper maintenance routine. However, these bearings can wear out prematurely if the furnace is overheating.

When should I worry about my furnace noise?

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.

Noisy Furnace? - Top 5 Fixes | Repair and Replace

Why does my furnace make a high-pitched sound?

High-Pitched Squeals: Often linked to the blower motor, these noises suggest failing bearings within the motor, requiring repair or replacement by an HVAC technician. A whistling sound, however, may point to airflow restrictions in the system.

What does a failing furnace sound like?

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.

Why is my heating making a whining sound?

Turn the unit off immediately and have a specialist inspect and or tighten. If the blower wheel or motor mount has broken, it will need replacement. A HIGH-PITCHED WHINING NOISE could be shaft bearings that need oil, or it could be a loose, slipping or frayed blower belt, which will need to be adjusted or replaced.

Why does my furnace fan make noise when I start it?

Furnace Makes a Loud Buzzing or Humming Noise

The main culprit would be an issue with your blower fan motor. If the sound is loudest during startup, this is very likely the reason. The fan motor may die, or the electrical components powering the fan may be worn out or faulty.

How do I fix my fan whine?

  1. Clean Your Ceiling Fan. Dirty blades can become unbalanced, making them noisy over time. ...
  2. Tighten the Fan Blade Screws. A ceiling fan making clicking noise may be caused by fan blades that aren't firmly attached to the fan assembly. ...
  3. Check Attached Lighting for Loose Screws. ...
  4. Examine the Fan Canopy. ...
  5. Add Oil to Your Fan.

Why is my furnace moaning?

A foreign object may be obstructing your blower, or one of the fan blades may be warped or broken. In either case, it can cause your motor to burn out. You'll need to call a technician to inspect your furnace and correct the problem.

How much is a new blower motor for a furnace?

While costs can vary, homeowners can typically expect the following range: Standard Blower Motors: These might cost between $400-700, excluding labor. Advanced Multi-Speed or Variable-Speed Motors: These are generally more expensive, with costs ranging between $650-1250, not including labor.

Why is my furnace whirring?

A common reason for furnace buzzing is a loose transformer box. A furnace transformer regulates the incoming voltage to an appropriate voltage for the furnace to use. This is more common after a new installation. With an older furnace, the transformer may be malfunctioning and needs to be replaced.

Why does my furnace sound like a motor?

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.

Why does my furnace whistle when it turns on?

If your blower motor is worn out or faulty, it can cause a high-pitched whistling sound due to increased vibration in the motor. This can lead to decreased airflow and higher energy bills. To fix this issue, you'll need to replace the motor with a new one.

Why does my furnace blower make a whining sound?

The most common causes of a loud or noisy blower fan are worn-out bearings, an out-of-balance blower wheel, a loose motor mount, a defective capacitor, a bent blower wheel, or debris buildup on the wheel.

Why is my fan making a weird noise when I turn it on?

A noisy ceiling fan is often a result of mechanical or electrical issues. A clicking noise from your ceiling fan could be caused by a few things. These include a loose blade, a bent blade arm, or a loose light fixture. If it hums or buzzes, it could be a problem with the motor or wiring.

What does a failing inducer motor sound like?

One of the first indicators that a furnace inducer motor is on borrowed time is if it's making odd noises. Sometimes it's a rattling noise, a clanking noise, chattering, pinging, shaking, a wobbling noise – you name it!

Why does my furnace make a noise when I start it?

Check the access panels to your furnace, and make sure each fits snugly and securely. Tighten any loose screws, if necessary. A couple of other reasons furnaces might make a rattling noise include dirty burners, a cracked blower motor fan belt or a loose or broken blower motor bracket.

How to fix high-pitched noise from furnace?

The blower may sometimes develop low airflow issues. Low airflow may cause the blower to strain to draw in enough air to be heated, resulting in whistling. If your furnace starts making a high-pitched whistling sound, consider changing your air filter or opening all vents to resolve the issue.

Why is my heating making a high-pitched noise?

A build-up of debris and limescale is a common cause, particularly in hard water areas. If you notice a build-up of limescale in your kettle, the same could be happening in your boiler. This build-up causes the flow of water in your boiler and heat exchanger to be restricted, leading to a high-pitched whistling noise.

What is the most common furnace failure?

One of the most common furnace problems is a malfunctioning thermostat. A sure sign your thermostat isn't working properly is if your fan is constantly running. This will cause your thermostat battery to run, and cause your furnace to work inefficiently.

Why is my furnace making a squealing sound?

A loose or aging fan belt can cause the fan to stop working properly. Since the belt is placed under a lot of stress, it can crack and eventually break. If the belt is failing, you may hear squeaking sounds or your central heating won't work at all until you have it replaced.

How much is a blower motor for a furnace?

Replacing a furnace blower motor costs $560, on average. Depending on the size and type of motor, most people pay $300 to $900. The average blower motor replacement cost is $560, but the final price depends on labor fees, as well as the cost of the parts.

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