Is It Normal to Smell Gas Near a Furnace?


Your furnace is one of your most-used appliances, especially during the chilly fall and winter months. Although your unit works hard to keep your home at a comfortable temperature, noticing an unusual smell coming from your system can seem alarming.

It’s not uncommon for homeowners to detect strange smells coming from their furnaces. In many cases, the smell of gas or other odors may point to a minor problem. However, it’s quite possible that these strange smells could point to a major issue that needs prompt attention. Following are a few common causes for a gas smell coming from the furnace and how you should respond if you do smell gas.

Turning on Your Unit After It’s Been Unused for Awhile

Your furnace sits unused during warmer weather. When you first turn your unit on again when temps turn cooler, it’s normal for accumulated dirt and debris that have settled in your furnace to produce a smell that could resemble gas. You can easily reduce the unpleasant smell by opening up your windows to allow for cross-ventilation.

However, if you notice a strong smell of gas in your home or if you hear a hissing noise, leave the house immediately. After getting everyone outside, contact your gas company. A strong smell of gas could be an indication of a gas leak.

If you smell gas only during certain times or in specific areas, there may be another explanation.

Normal Gas Emissions Produced by Your System

Each time your furnace cycles on, it emits a small amount of gas. As long as you occasionally notice a faint gas smell near your unit whenever it cycles on, you probably don’t have anything to worry about. If you frequently smell gas near your furnace, you could be dealing with a dangerous gas leak. In this case, your best course of action would be to turn your furnace off and contact an experienced HVAC technician to correct the problem immediately.

A Cracked Heat Exchanger

The heat exchanger is the part of your furnace that actually produces heat. Over time, prolonged use of your system could cause the heat exchanger to become cracked. If this happens, combustion gases could mix with the heated air that’s produced by your system and cause it to circulate throughout your home. A cracked heat exchanger could put your family at serious risk, especially because it may allow carbon monoxide to enter your home. This is a problem that you’ll want to address as soon as possible.

Smells Caused by the Exhaust Pipe

Smelling a gas smell coming from the exhaust pipe of your unit is completely normal. This pipe is responsible for expelling excess gas that may not have been completely used by your system. Sometimes, you might simply be smelling gas that’s expelled by the exhaust pipe because air is blowing back into your home through a door or an open window. If you detect a faint smell of gas, you might just need to close your windows or door whenever the wind is blowing in a certain direction.

Compromised Vents

When your heating equipment and vents are properly maintained, the risk of a backdraft is minimal. Normally, your furnace draws heated gases up to the vent on top of your roof where they are safely discharged into the air. If your flue is compromised, back-drafting can cause these harmful gases to reverse their courses back down through the vent pipe and into your home. Some of the most common causes of back-drafting include:

  • A clogged or leaky flue
  • Leaky air ducts
  • The use of too many exhaust fans at one time

Other Reasons for Gas-Like Smells

It’s possible that the gas-like smell that you’re noticing isn’t even coming from your furnace. There are several things that could be causing a pungent smell associated with a gas leak. If you enjoy grilling and if your propane grill is left near an open window, the smell could definitely mimic the smell of a gas leak. Many homeowners who use gas stoves have also mistaken a smell coming from their burners for a gas leak, too.

Experienced Technicians at Your Service

Keeping a well-maintained furnace is highly important. If you’ve put off scheduling regular furnace service, contact the professionals at [company_name]. Dedicated to unbeatable customer service, we regularly assist customers in Meridian, McCall, and the surrounding communities. Our friendly and skilled technicians also specialize in performing other services, including heating, cooling, and electrical repairs, installations, and maintenance services. We look forward to serving all of your home climate comfort needs.