Gas smell near the furnace

Symptoms

• Rotten-egg or sulfur smell near the furnace or gas lines
• Smell may be constant or intermittent
• May be accompanied by a hissing sound

Likely causes

• CommonLoose or failed gas fitting or connectionFittings can loosen over time from vibration or age and leak small amounts of gas.
• PossiblePilot light out with gas valve still allowing some gas flowAn extinguished pilot on an older furnace can let unburned gas smell build up nearby.
• PossibleCracked or damaged gas lineCorrosion or physical damage to the line can create a leak.
• Less commonFaulty gas valve on the furnaceInternal valve failure can allow gas to escape even when the furnace is off.

What to do

1. Leave the house immediately, taking others and pets with you; don't flip light switches or use your phone until you're outside.
2. Once outside and at a safe distance, call your gas utility's emergency line or 911.
3. Don't attempt to locate the leak, light anything, or turn any switches on or off inside.
4. If you know the location and it's safe to do so on your way out, shut off the main gas valve at the meter.
5. Wait for the gas utility or fire department to confirm it's safe before going back inside.
6. Once cleared, have a licensed technician inspect and repair the furnace or gas line before using it again.

When to call a pro

Always a licensed technician and your gas utility — never attempt to find or fix a gas leak yourself.

Safety