Are Loud Banging Noises From Your Furnace An Emergency?

Posted on: 7 July 2023

Determining when to make an after-hours emergency call to an HVAC contractor can often be nerve-wracking. On the one hand, you want to fix any problems that may pose a safety hazard or leave you dealing with dangerously cold temperatures. On the other hand, making an unnecessary emergency call can mean spending more money than necessary to fix a problem.

Of course, of the many problems your furnace might experience, loud noises can often be the most disturbing. If you can hear loud bangs when your furnace turns on or during its normal operation, should you make an emergency call to an HVAC technician?

What's Making Your Furnace Go Bump In the Night?

Furnaces can make numerous noises, and some of them are perfectly normal. Aging furnaces will also be a bit noisier, and this louder operation isn't always a cause for concern. However, loud bangs are never part of your furnace's normal operation. In nearly every case, these noises are exactly what they sound like: small explosions occurring as your furnace ignites.

This condition is known as delayed ignition. Under normal circumstances, your furnace's burners will supply the correct amount of gas for quick and efficient ignition. You might hear a "whoosh" near the furnace as the burners ignite, but this noise should be barely perceptible elsewhere in the home. Loud bangs occur when gas accumulates before igniting, creating a much more violent explosion.

How Worried Should You Be About Delayed Ignition?

The simple answer is that delayed ignition is a harmful and potentially dangerous condition. Those bangs or pops can stress numerous components in your furnace and may cause damage to your burners or even your heat exchanger. Since cracks in the heat exchanger can allow hazardous carbon monoxide to escape, this is a problem that you shouldn't ignore.

Delayed ignition also drastically reduces your furnace's efficiency. Your furnace requires a clean, steady, continuous burn to heat your home efficiently. Delayed ignition ultimately causes your furnace to use more fuel while delivering poorer and less consistent performance. Even without causing additional damage, delayed ignition problems can cost you money.

Should You Treat Delayed Ignition As an Emergency?

As with many furnace issues, the answer as to whether to treat delayed ignition as an emergency will depend on your circumstances. However, you should not use your furnace while you can hear popping or banging noises. Damage to your heat exchanger can occur suddenly, and you won't have any way of knowing if you already have one or more dangerous cracks.

Since you won't be able to use your furnace until a technician can investigate, you should consider delayed ignition an emergency if conditions are very cold. Low temperatures can be incredibly dangerous, so spending a little extra to schedule an emergency visit can allow you to safely restore your heat and protect your family against the bitter cold.

For more information, contact an emergency furnace repair service near you.