How to Listen for Your Furnace: Common Noises That Need Repairs

The sudden switch to cold weather is jarring, and that’s just as true for your furnace. If you’ve recently started turning your furnace on on full-time, you might notice, the wide array of clanks, whirrs, and rattles are louder than you remember. Listen for these odd noises to see if your furnace needs repairs before the next snow storm.

Is the furnace chirping?

This noise is noticeable because it’s not quite clear that it’s coming from your furnace at first. But even though it’s one of the most noticeable noises, it doesn’t necessarily mean that something is wrong. Oftentimes, the chirp is just the furnace getting used to working after a long off-season. But if it continues to chirp, a technician will need to check the fan and other components.

Do you notice a lot of heat cycles?

We’ve all heard the rattling gust of a heating system turning back on to full power. You’ll usually hear this when you bump up the thermostat or after sundown when the temperature drops. If you hear it continuously running throughout the day, your heater is going through more heat cycles than it should. Not only is that a huge drain on your energy bill (reheating a room requires a lot more energy than maintaining a relatively constant temperature), it could mean something is wrong with your thermostat or furnace. Contact an expert to get things checked out.

Is your pilot light clicking?

Any unusual noises near the flame should be investigated immediately. A clicking usually means the flame sensor is broken or dirty. There could be a malfunctioning connection between the gas and the ignition point. This doesn’t necessarily mean there’s a problem with the natural gas, you should be particularly vigilant about any signs of natural gas seeping into your home. Call a technician and make sure your carbon monoxide detector has working batteries.

What about banging and clanging?

Loud noises always sound like something has gone drastically wrong, no matter what part of your house it is. But if you hear metallic thuds, even ranging from quiet pops to attention-getting bangs, it might just be the ducts expanding and contracting as the furnace turns on and off. You’ll hear the same sort of sound from your attic as the wooden rafters expand and contract. If the louder bangs don’t follow changes in temperature, it’s more likely to be something that needs to be looked at. Have a technician check your burners and gas valve for any build-up of dirt or defects.

Do you hear whining that gets louder as you get closer to your furnace?

A quick proximity check can help you narrow down the list of likely suspects for any sound (especially with the previous example because you can hear if where the bang originates from), and a whining sound is easy to find the origin point for. If you hear it loudest near where the blower motor is, that part needs to be repaired or replaced. If you hear it more clearly on other sides of the furnace, then the inner workings need lubrication.

Most furnace noises are signs of problems slowly building; even if something isn’t broken, it needs attention. The best way to minimize your furnace’s noises is through preventative maintenance and an annual tune-up. If your furnace is making unusual noises or you want to make sure it doesn’t start making noise, go to Metro Heating & Cooling to set up an appointment.