When your furnace is operating properly, it should give warmth without generating too much sound. While it’s normal to hear your furnace making noise as it starts up, other sounds are signaling your furnace should get immediate professional help.

Here are some of the most reported furnace noises and what they could mean. If your furnace is making a weird noise, our friendly heating pros are here to fix the problem with the best furnace repair in Frederick, Maryland.

1. Furnace Makes Banging or Knocking Sounds

You may have a serious issue on your hands if you’re hearing your furnace making a banging noise. If your furnace is making a knocking noise, it can indicate there could be a couple of problems. These range from gas accumulating in your furnace or a ductwork issue.

Banging Sounds Coming from Your Furnace

Your heating system gets grimy over time, so that’s why it’s critical to schedule seasonal furnace maintenance with May's Heating & Air. One of the jobs our pros complete during this service is clean your furnace’s burners. When this piece gets dirty, you could hear your furnace making a loud rumbling noise after ignition takes more time. The ensuing gas buildup can fracture your furnace’s heat exchanger, where natural gas turns into heat. Any cracks in it can discharge carbon monoxide, which is normally vented outside. This toxic gas can be deadly in large concentrations.

If you’re hearing banging or knocking sounds coming from your furnace, May's Heating & Air recommends turning it off and contacting us at 301-690-0397. Significant natural gas in your furnace or a broken heat exchanger are serious issues that should get fast attention.

Banging Sounds Coming from Your Ductwork

Your furnace works with ductwork to move heated air around your house. If the ductwork wasn’t put in properly or is aging, it can be noisy when your furnace is on. This can be the problem if your furnace makes a banging noise when it shuts off. Call May's Heating & Air at 301-690-0397 and we’ll pinpoint the problem.

2. Furnace Making a Buzzing Noise

If you notice your furnace making a buzzing noise, don’t delay calling us. A buzzing sound usually is telling you there’s an electrical issue, like with its transformer, blower motor or capacitor.

Your furnace relies on an internal transformer to work on the correct voltage. If wires or the box isn’t tight enough, you could detect a low humming noise in the furnace when off. Your furnace also has a blower motor, which distributes warm or cold air throughout your space, and a capacitor, which starts the motor. If either of these pieces are fading, they will buzz when the furnace starts.

3. Furnace Making a Rattling Noise

If your furnace is making a rattling noise, it could be due to something minor, like an unfastened screw, or something major, like a broken part. In either case, we recommend shutting off your furnace and getting in touch with our heating professionals at 301-690-0397 for support.

4. Furnace Is Making a High-Pitched Squealing Sound

If your furnace makes a high-pitched noise, like squealing, when it’s heating, it’s making an effort to get your attention it requires some TLC. If you’ve forgotten furnace maintenance recently, belts could be worn down or a bearing could need to be lubricated. We realize that maintenance often slips your mind, but our technicians can get your furnace heating quietly again fast.

5. Furnace Makes a Whistling Sound Like Air Escaping

When you’re hearing your furnace making a whistling noise, it’s typically because of an air leak in your ductwork. You might also be aware of whistling while the furnace is running if a floor vent isn’t secure. If you’ve checked your vents but are still sensing noise, May's Heating & Air can help. It’s essential to get loose ductwork repaired quickly, as it can result in comfort problems in your home and inflate your energy costs.

6. Furnace Making a Grinding Noise

It’s not a good sign if you hear your furnace making a grinding noise. This metal-on-metal noise often means there’s trouble with your furnace’s blower. Switch off your furnace off promptly and call our professionals at 301-690-0397 for help.

When you’re noticing an uncommon noise from your furnace, May's Heating & Air is available to support you. Contact us at 301-690-0397 to request your furnace repair appointment today.