When you notice a leak around your furnace, the first step is to determine what you’re dealing with — water or gas. The two issues are different, and knowing which one you have is critical.

A furnace gas leak usually makes itself known through a strong rotten egg or sulfur smell. This odor is added to natural gas as a warning sign. If you detect it, treat it as an emergency. A furnace water leak is far less urgent but still needs attention. Pooling water near the base of your unit or dripping from connected lines usually signals a problem in the condensate system. If you smell gas, skip everything else and follow the emergency steps outlined below right away. 

What to Do Immediately for a Furnace Gas Leak

A furnace gas leak is dangerous. Your safety and your family’s safety come first. Take these steps:

  1. Do not turn on or off any lights, appliances, or electronics.
  2. Extinguish candles, pilot lights, or any other open flames.
  3. Evacuate everyone from the home immediately.
  4. Once you’re at a safe distance, call 911 and then your local gas utility company.
  5. Only after the situation is secure should you arrange professional service for leaking furnace equipment.

Common Causes of a Furnace Water Leak

Unlike gas, water is a natural by-product of high-efficiency furnaces. But excess moisture or standing water means something isn’t working right. Common causes of a furnace water leak include:

  • Clogged condensate drain line: Dirt and debris block the line, forcing water to back up.
  • Condensate pump malfunction: If the pump fails, it can’t move water away from the unit.
  • Humidifier problems: A whole-home humidifier connected to your system can leak into or around the furnace.
  • Cracked heat exchanger: This serious issue requires immediate professional attention.

Your Action Plan for a Leaky Furnace

If you’ve confirmed it’s a water leak, here’s what you can do:

  1. Turn off the power: Shut down the furnace at the thermostat and circuit breaker.
  2. Clean up the water: Use towels or a wet-dry vacuum to limit damage.
  3. Check the filter: A wet or clogged filter can worsen the issue.
  4. Inspect the condensate line: Look for obvious clogs or disconnections.

Don’t Risk It: Call the Professionals at One Hour Heating & Air Conditioning®

Even if the problem seems minor, a furnace leaking water can signal bigger issues. Repairing a heat exchanger or replacing a pump isn’t a DIY project — it requires trained technicians. At One Hour Heating & Air Conditioning®, we provide fast, reliable service for leaking furnace systems, including emergency care.

Book now or contact us today for expert furnace repair you can trust. Let us help you today.