Most mechanical devices make some noise when operating. Think about the low hum of your refrigerator, the clicking sound as you fire up your gas stove, or the wooshing sound of your dishwasher in action.

Your furnace is no different. It is designed to communicate with you when it cycles on and off, so you know all is well. But sometimes your furnace can make some noises that are not part of its normal operation. In fact, some noises can indicate an issue with your furnace that can put you and your home at risk.

Here are five noises that indicate your furnace needs attention.

 1. Boom or Bang

This may be one of the most unsettling sounds you can hear from your furnace. While it’s not uncommon to hear a furnace engage, a loud boom or bang could indicate the buildup of gas from a delay in the ignition. Under normal circumstances, when the thermostat triggers your furnace to engage, gas valves open and the burners ignite. However, sometimes the burners don’t ignite right away and gas builds up as a result. When the burners finally ignite, it creates a small explosion, resulting in a loud booming sound. If you hear this sound, call a professional service technician immediately, especially if there is an odor of natural gas around the furnace.

 2. Popping or Clicking

In older furnaces, small clicking or popping sounds are simply the sound of the warm air changing the air pressure inside your ducts and air vents. However, they can also indicate a more serious problem. For example, a popping sound could mean that your furnace burners are dirty and may need cleaning. A constant clicking might signal that your heat exchanger is cracked, which is something you’ll want to tend to right away as it’s one of the leading causes of residential carbon monoxide poisoning.

 3. Squealing or Whistling

A high-pitched squeal could mean several different things. For example, it could indicate a faulty belt or that there’s an issue with a motor bearing in your blower. Over time, bearings can become worn out and need to be replaced to prevent the motor from overheating. However, if your furnace is making more of a whistling sound, it could be due to an air-flow issue, like a dirty air filter, obstructed air vent, or a damaged duct. Open your vents and change your filter. If the noise persists, call a technician to investigate further.

 4. Rattling

There are a number of different reasons why a furnace might be rattling, some of which are more severe than others. For example, a rattle could indicate that there are loose bolts in the access hatch that simply need a quick tightening up. A rattle might also point toward a crack in your heat exchanger, burner, or blower motor fan belt. For this, you’ll want to have a technician diagnose the problem ASAP and perform any necessary repairs or replacements.

 5. Chirping

Chirping noises are common in a furnace that hasn’t been used in a while. If you hear chirping, and it’s the beginning of the heating season, wait a bit. If the chirping doesn’t go away, it might mean that the pulley for the blower motor is out of alignment or that the mounting plate is touching the blower wheel. Again, if it doesn’t seem to go away after the furnace starts up, you’ll want to call a pro to have a look.

When you hear noises that aren’t part of normal operation, contact the professional heating technicians at Zach Heating & Cooling. We have to tools and expertise to decipher what your furnace is trying to tell you and remedy the problem so you can rest easy all winter long.