Furnace troubleshooting: Symptoms of a faulty gas furnace

When your gas furnace turns itself off without heating the home or you notice a pungent gas odor in...

When your gas furnace turns itself off without heating the home or you notice a pungent gas odor in the home, it's time for a little furnace troubleshooting. We rely on central heating units to simply work, but sometimes things go wrong over those long summer months. Ready for some answers? Dan Jape of Reliable Heating & Air in Atlanta has 'em!

"Some symptoms of a faulty furnace can be a flicking flame, a loud explosion or boom when the furnace first ignites or a pilot light that goes out over and over again," Jape explained during an interview.

So what causes these problems? Routine wear and tear on the interior of the furnace is usually the culprit. Here's what to look for.

Symptom 1: Rust build-up in the heat exchanger

When an HVAC technician services your gas furnace before the start of winter, he will check for rust, cracks and leaks in the heat exchanger. Corrosion occurs as the natural gas burns and turns into a harmful gas that rusts the interior of the furnace.

"The damage caused by the gases have to be monitored carefully to be sure the furnace is not damaged to the point it is unsafe to use," Jape explains on his company's blog. "If these items are performed regularly, a furnace should be able to provide many years of trouble free and safe heat for your home."

Symptom 2: Furnace turns off intermittently

So, you've turned on the furnace, the warm air starts to heat your home and it clicks off. If this happens over and over again, your fan or blower may be malfunctioning. Or, a failing high temperature limiting switch may be to blame.

"If a fan or blower stops operating on a furnace, the gas will continue to ignite until these limit devices sense the furnace is overheated and shut off the burners and turn the furnace off. These limit switches are directly in the air stream and take a lot of abuse and they fail after a number of years," Jape commented in his blog post "It's not just "routine" maintenance this time of year.".

Symptom 3: An odd odor each time the furnace turns on

Do you notice a gas-like odor each time the furnace turns itself on? Although a slightly dusty smell is normal at the start of the heating season, ongoing odors are not. This is a sign your draft inducer may have a crack or leak.

"Some manufactures make the housing of these inducers out of plastic and they become so hot, the plastic housing cracks allowing flue gases to be emitted into the living space of a home," Jape explained in his blog post. "These units need to checked at the start of every season for proper operation and integrity of the housing."

Having issues with your furnace? Call the HVAC professionals at Reliable Heating & Air to diagnose the problem. Furnace troubleshooting is best left to the experts!

Popular on Kudzu

  1. How much could I pay for carpet cleaning?
  2. DIY Network Video: Easy Garage Door Check-up
  3. Video: How do I choose a garage door?
  4. How much does it cost to install new gutters?
  5. Incredible Lighting in 4 Steps

ENJOY THIS ARTICLE? Sign up for more articles, tips and savings

From Our Experts

Kudzu Category Sponsors