Skip navigation

Serving Middle Georgia Since 2001

Middle Georgia's Choice

Family-Owned & Operated Since 2001


Premier Heating & Air Blog

Why You Have a Hissing Heater


In an ideal world, the appliances that make our homes comfortable would operate quietly and efficiently. When they’re not running quietly, it’s usually a sign that something is wrong. 

Depending on the noise your heater is making, there could be a number of things going on. In this article, we’re going to specifically examine hissing noises. No, there’s not a snake in your heater and it isn’t mad at you. To determine if a heating repair is in order, let’s take a look at the possible reasons for a hissing heater. 

  • The air filter is clogged: A hissing sound occurs as airflow is being obstructed and forced through a dirty air filter. This is the easiest problem to fix as all you’ll need to do is change that dirty air filter.
  • There is a buildup of dirt on the heating elements: If you have an electric furnace, debris that collects on the heating coil can cause a hissing noise and is usually accompanied by the smell of burning dust.
  • There is a leak in the ducts: You’re probably noticing that airflow impediments are often the cause of a hissing sound. If there are leaks in your home’s ductwork, it can create a hissing noise as the hot air escapes into walls or crawlspace.
  • You have a cracked heat exchanger: If you have a gas furnace, the hissing sound could be due to a crack in your heat exchanger. This is a serious issue and one we’ll examine in more detail.

How To Tell if You Have a Cracked Heat Exchanger

When your furnace burns natural gas, it creates combustion gases that are sent to the heat exchanger. The heat exchanger, a metal component, then heats up and warms the air blown around it. If there’s a crack in the heat exchanger, those harmful combustion gases can escape, putting your health and safety at risk. If you smell gas or feel dizzy or nauseous, turn the system off immediately and call for emergency help before getting repairs scheduled.

Additional Signs of a Cracked Heat Exchanger

The hissing noise isn’t the only symptom when a heat exchanger has developed a crack. Here are some additional symptoms to be aware of that will alert you to this problem.

  • Inefficient heating: Less gas to heat up the heat exchanger means less warm air getting to your home.
  • Bad smells: Strong and unpleasant orders such as sulfur, formaldehyde, or rotten eggs when you run your heater.
  • Presence of carbon monoxide: One of the gases that enter your heat exchanger is carbon monoxide (CO) and when it’s leaking through the crack can cause symptoms such as dizziness, fatigue, nausea, and headaches.

If you have a furnace that has developed a cracked heat exchanger, you should contact a professional for repairs ASAP. Only an expert has the tools to diagnose and fix this issue correctly and safely.

The maintenance and repairs offered by our team will help keep your furnace running smoothly and will address any repair needs promptly.

Contact Premier Heating & Air to schedule an appointment. Experience the Premier Difference.

Comments are closed.