5 Common Furnace Noises & What They Mean

A noisy furnace can quickly ruin your peace and relaxation at home, but the good news is that furnace sounds are often early warning signs of bigger problems to come. Figure out the source of the noise, and we’re on our way to finding a solution.

As always, be careful when troubleshooting a furnace — especially if the problem may be related to the gas line in any way. When the solution calls for more than changing the air filter or tightening some screws that are easily within reach, call our furnace repair experts to set things straight.

1. Popping or Banging at Start-Up

Like an engine misfiring, you might hear a furnace popping, booming, or banging as it starts up. This is not normal — for an oil or gas furnace, it might mean that the burner is struggling to reach a hot enough temperature to combust the fuel. That causes fuel to build up, and when the burner does get hot enough it pops the excess gas or oil.

Do you hear popping or banging when the unit cycles off, too? In that case, you might actually be hearing ducts pop as they expand or contract with temperature changes. Ductwork maintenance can alleviate this problem if it’s too annoying to live with.

2. Dry Squealing

Belts or bearings produce a squealing sound when they need lubrication or replacement. Call a furnace repair technician to handle this, because it’s more complicated than you might think. The furnace will need cleaning and a quick tune-up to remove grime and inspect for broken or failing parts.

3. Rattling or Rumbling

We need to figure out the source of the noise to troubleshooting a rattling or rumbling furnace. Causes include loose debris, loose ductwork, a broken fan blade, or more serious problems with the motor.

4. Clicking

A clicking furnace becomes annoying fast, but it’s good to become aware of this issue. Clicking sounds tend to come from the ignition or heat exchanger. You’ll want to get furnace repairs ASAP, either way. If those parts are working fine, you probably just need a furnace tune-up to stop nuts, bolts, and other fixtures from clicking.

5. Whistling or Vibrating

Persistent whistling often indicates that the air intake or air filter is clogged or dislodged, causing the moving air to make noise. If there’s whistling or vibrating sounds from the vents, however, the ductwork may be loose and allowing air to escape. A good inspection of the airflow system can stop the noise and potentially improve the furnace’s efficiency.

Get Help with Furnace Repair in St. Louis

Is your noisy furnace preventing you from relaxing or getting a good night’s sleep? Our St. Louis furnace repair technicians can help with a quick fix. Call 314-845-5900 or contact us online to request friendly, honest service from Metro Heating & Cooling.