It’s normal for your HVAC system to emit some level of noise. Heating and cooling a home requires multiple components to function simultaneously, and no electrical or gas-powered unit can operate without being at least somewhat audible. But when that noise sounds unusual, it may be cause for concern.

At Steve’s Plumbing & Heating, we know HVAC systems are a mystery for most homeowners who have them, and that’s okay. If you’re not a trained heating and cooling professional, you can’t be expected to understand the inner workings of your system.

But what you should understand is how to tell when your system may be experiencing a potentially serious issue. Let’s take a look at four of the most common HVAC noises and what they typically indicate.

Squeaking or Squealing

High-pitching squeaks or squeals usually indicate a problem with your unit’s motor. The problem may be the blower motor or fan motor, but it’s difficult to tell based on the noise alone.

It’s important to note that some units produce a high-pitched noise when they first come to life after a prolonged period of downtime. If you’ve just restarted your unit, wait a little while to see if the noise dies down. If it doesn’t schedule a service appointment with a heating and cooling professional as soon as you can.

Tending to heater or air conditioner repairs promptly is the best way to avoid further damage to the unit.


If you notice a loud hissing noise while your heater or air conditioner operates, that usually indicates a leak somewhere in the system. There could be a small hole in the ductwork or a leak might be present somewhere else. Given the size of the average HVAC system, there are several areas that must undergo inspection to ensure all possible leaks are addressed.

Don’t wait to call a heating and cooling professional when you notice hissing sounds. If air is escaping your HVAC system, that means it isn’t getting into your house. The more air that escapes, the higher your monthly energy bills will be.


Popping sounds may be nothing to worry about if you haven’t used your HVAC system in a while and you have metal ductwork. When warm and cold air move through metal ducts, the metal can contract and expand, especially if the system recently saw a prolonged period of inactivity. If the sound appears to be coming from your ductwork, it should die down as the ducts readjust.

If the noise persists or appears to be coming from another location, contact a heating and cooling professional for an HVAC inspection.

Shrieking or Screaming

If your HVAC system ever makes a high-pitched, whistle-like, screaming noise, turn it off immediately. This is never normal and you need to have the system examined by a qualified heating and cooling repair specialist immediately.

When these types of noises occur, they may indicate excessive internal pressure in the compressor or a refrigerant leak in your air conditioner. Both issues can cause serious, potentially irreparable damage to the unit and may even impact you and your family members’ health.

Steve’s Plumbing & Heating: Expert Heating & Cooling Specialists at Your Service

If you're having heating or cooling issues in your Central Wisconsin home, get in touch with our team at Steve’s Plumbing & Heating right away. Since 1985, we’ve proudly served the HVAC needs of homeowners throughout Wisconsin Rapids, Stevens Point, Marshfield, and Wausau, and when you need us, we’re here for you too. 

To schedule service or learn more about how we can help, give us a call today at 715-421-1800 or contact us online. You can also request an estimate, and we’ll be in touch!