Is Your Furnace Making Strange Sounds? How to Troubleshoot & Fix Furnace Clicking, Humming, or Whistling

furnace strange sounds troubleshooting

It can be more than a little concerning when your furnace starts making strange sounds, especially during the cold months of the year. Here in Northern Colorado, the winters can be very cold as you likely already know—so if you’re hearing something unusual from your furnace, remember that you can schedule an emergency repair service call from us if necessary.

In this post, we’ll tell you about the most common causes for unusual sounds from your furnace, whether or not you’re likely to be able to fix those things yourself, and what to do. However, safety comes first whenever dealing with an HVAC system, so before we get started, let’s quickly discuss how to identify a gas leak.

Very Important: Unusual Sounds Might Indicate a Potential Gas Leak

Before we dig into the rest of this post, it’s very important note that while plenty of furnace issues can be resolved with a “DIY” approach, if you’re not absolutely sure what you’re doing, you’re probably better off giving us a call. If you suspect you might have a gas leak, the only number to call is 9-1-1 after you’ve evacuated your house.

Unusual sounds from your furnace could simply be an indication that the device is in need of routine maintenance. However, some sounds can also be indicative of a gas leak. Roaring, hissing, or whistling sounds can sometimes indicate a gas leak, especially if you smell natural gas in the area (it has a rotten egg scent).

Before moving on, please take a moment to review these guidelines from Energy.Gov on how to respond to a natural gas leak.

These Possible Issues Might be Causing Furnace Clicking Sounds

furnace humming

The clicking you hear from your furnace is usually caused by the igniter—when your furnace first fires up, you might hear a few clicks (similar to when you start a gas stove). With that in mind, there are two situations where you might hear clicking from your furnace: either the heat is working, or it is not.

If the heat isn’t working, and you hear the usual clicking sound of the igniter, the problem might be a problem with the wiring of the igniter, or the unit itself might be damaged. In the worst case scenario, it means that there’s no gas to ignite, and that’s a sign of a leak. Please refer to the previous section if you find yourself in this situation.

It can be more than a little concerning when your furnace starts making strange sounds, especially during the cold months of the year. Here in Northern Colorado, the winters can be very cold as you likely already know—so if you’re hearing something unusual from your furnace, remember that you can schedule an emergency repair service call from us if necessary.

In this post, we’ll tell you about the most common causes for unusual sounds from your furnace, whether or not you’re likely to be able to fix those things yourself, and what to do. However, safety comes first whenever dealing with an HVAC system, so before we get started, let’s quickly discuss how to identify a gas leak.

Very Important: Unusual Sounds Might Indicate a Potential Gas Leak

Before we dig into the rest of this post, it’s very important note that while plenty of furnace issues can be resolved with a “DIY” approach, if you’re not absolutely sure what you’re doing, you’re probably better off giving us a call. If you suspect you might have a gas leak, the only number to call is 9-1-1 after you’ve evacuated your house.

Unusual sounds from your furnace could simply be an indication that the device is in need of routine maintenance. However, some sounds can also be indicative of a gas leak. Roaring, hissing, or whistling sounds can sometimes indicate a gas leak, especially if you smell natural gas in the area (it has a rotten egg scent).

Before moving on, please take a moment to review these guidelines from Energy.Gov on how to respond to a natural gas leak.

These Possible Issues Might be Causing Furnace Clicking Sounds

how to fix furnace clicking sound

The clicking you hear from your furnace is usually caused by the igniter—when your furnace first fires up, you might hear a few clicks (similar to when you start a gas stove). With that in mind, there are two situations where you might hear clicking from your furnace: either the heat is working, or it is not.

If the heat isn’t working, and you hear the usual clicking sound of the igniter, the problem might be a problem with the wiring of the igniter, or the unit itself might be damaged. In the worst case scenario, it means that there’s no gas to ignite, and that’s a sign of a leak. Please refer to the previous section if you find yourself in this situation.

Otherwise, if the heat is working but you’re still hearing clicking, it might be the inducer or flame censor, both parts that can be quickly and easily replaced by an HVAC professional.

A Humming Furnace Sound Might Have an Easy DIY Fix

Humming from your furnace usually indicates one of two things: there’s a loose duct work somewhere in or nearby the unit, or the blower motor is struggling. Loose ducts can be easy or hard to fix, depending on where they are. To fix leaking ducts, check out our post Solving an Expensive Problem: DIY Repair Guide to Fixing Leaky HVAC Ducts.

If the humming is coming from the motor, it doesn’t necessarily mean that failure is imminent—the motor might simply need lubrication. If the hum goes away when the blower isn’t running, that’s probably the culprit. Give us a call and we can take care of it for you.

Furnace Whistling? In Our Experience, It’s Probably One of These Things

As we mentioned previously, whistling when accompanied by the smell of rotten eggs is a fairly strong indicator of a gas leak—please see the section above about what to do in those situations.

Otherwise, whistling can be caused by something as simple as air escaping somewhere in the system. For example, if you have a leak in the ductwork, you might hear a whistling sound. Refer to the post mentioned above to repair duct leaks.

Can’t Figure Out That Sound? Best Buy Heating and Air is Here to Help

If this post didn’t lead to the resolution of your problem, you might want to also check out our blog post DIY Tips: How to Identify & Fix Common Furnace Problems Before Winter where we discuss a handful of other issues, including thermostat troubleshooting, how to identify and check whether or not the furnace safety switch has been accidentally tripped, and more.

If the problem with your furnace isn’t so much a sound as a matter of not providing enough warmth, or only adequately warming certain areas of the home, the issue might actually be air balancing. Take a look at our post Prevent Hot and Cold Spots With These Easy DIY Air Balancing Techniques to learn how to resolve this (very) common issue.

Having said all that, if you can’t figure out what’s going on with your furnace, there’s one solution that’s guaranteed to work… calling us!

Please feel free to give us a ring at (970) 218-0414 or request a service appointment online.

If the heat isn’t working, and you hear the usual clicking sound of the igniter, the problem might be a problem with the wiring of the igniter, or the unit itself might be damaged. In the worst case scenario, it means that there’s no gas to ignite, and that’s a sign of a leak. Please refer to the previous section if you find yourself in this situation.

Otherwise, if the heat is working but you’re still hearing clicking, it might be the inducer or flame censor, both parts that can be quickly and easily replaced by an HVAC professional.

A Humming Furnace Sound Might Have an Easy DIY Fix

Humming from your furnace usually indicates one of two things: there’s a loose duct work somewhere in or nearby the unit, or the blower motor is struggling. Loose ducts can be easy or hard to fix, depending on where they are. To fix leaking ducts, check out our post Solving an Expensive Problem: DIY Repair Guide to Fixing Leaky HVAC Ducts.

If the humming is coming from the motor, it doesn’t necessarily mean that failure is imminent—the motor might simply need lubrication. If the hum goes away when the blower isn’t running, that’s probably the culprit. Give us a call and we can take care of it for you.

Furnace Whistling? In Our Experience, It’s Probably One of These Things

As we mentioned previously, whistling when accompanied by the smell of rotten eggs is a fairly strong indicator of a gas leak—please see the section above about what to do in those situations.

Otherwise, whistling can be caused by something as simple as air escaping somewhere in the system. For example, if you have a leak in the ductwork, you might hear a whistling sound. Refer to the post mentioned above to repair duct leaks.

Can’t Figure Out That Sound? Best Buy Heating and Air is Here to Help

If this post didn’t lead to the resolution of your problem, you might want to also check out our blog post DIY Tips: How to Identify & Fix Common Furnace Problems Before Winter where we discuss a handful of other issues, including thermostat troubleshooting, how to identify and check whether or not the furnace safety switch has been accidentally tripped, and more.

If the problem with your furnace isn’t so much a sound as a matter of not providing enough warmth, or only adequately warming certain areas of the home, the issue might actually be air balancing. Take a look at our post Prevent Hot and Cold Spots With These Easy DIY Air Balancing Techniques to learn how to resolve this (very) common issue.

Having said all that, if you can’t figure out what’s going on with your furnace, there’s one solution that’s guaranteed to work… calling us!

Please feel free to give us a ring at (970) 218-0414 or request a service appointment online.

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