Updated October 2026. If you smell gas near your furnace, leave the home now with everyone, including pets, and call your gas utility or 911 from outside. Don’t flip light switches, unplug anything, use a phone inside or start a car in an attached garage on the way out, because a spark can ignite gas. Puget Sound Energy (PSE) customers call 1-888-225-5773; Cascade Natural Gas customers call 888-522-1130. Stay out until the utility or fire department tells you it is safe.
Smell gas? Do this now
- Get everyone out, including pets. Leave the door open behind you.
- No light switches, plugs, phones, lighters, garage door openers or cars on the way out.
- From outside, call your gas utility (PSE 1-888-225-5773 or Cascade 888-522-1130) or 911.
- Don’t go back in, and don’t turn the gas or the furnace back on yourself, until the utility says it is safe.
This guide covers what happens next: which utility to call, whether a faint smell is ever normal, what makes a furnace smell of gas, and how to get your heat back once the utility has been out. To book a repair after the all-clear, see emergency furnace repair.
Which gas utility do I call?
Your gas bill names your utility. In the Puget Sound area it is usually PSE or Cascade Natural Gas. If you are not sure who to call, call 911.
| Who | Number | What they say |
|---|---|---|
| Puget Sound Energy | 1-888-225-5773 | Leave, then call PSE or 911 from outside. PSE sends a technician at no charge. |
| Cascade Natural Gas | 888-522-1130 | Evacuate everyone including pets, leave the door open, call from outside or call 911. |
| Any time you’re unsure | 911 | Call from outside, away from the home. |
Sources: PSE, detect a leak; Cascade Natural Gas, emergency information. Checked October 2026.
Should I open the windows? Not if it means staying inside. Cascade says not to open or close windows; leave and let the utility ventilate. Getting out is what matters.
Is it normal to smell a little gas from a furnace?
Natural gas has no smell of its own. Utilities add an odorant that smells like rotten eggs so people notice a leak (PSE); NW Natural names it as mercaptan, which is safe to breathe in the tiny amounts used. Some homeowners notice a faint whiff right as a furnace or stove lights. That can happen, but you can’t tell a harmless whiff from a real leak by nose alone.
Our advice is simple: if you smell gas and it doesn’t clear right away, or you smell it when nothing is lighting, treat it as a leak. Leave and call the utility. A dusty or burning smell the first time the heat runs in fall is different; see why your furnace smells when you turn it on for those.
Why would a furnace smell of gas?
Once the utility has made the home safe, a technician finds the cause. These are the usual suspects:
| Possible cause | What’s going on |
|---|---|
| Delayed ignition | Gas flows for a moment before the burners light, often from a weak ignitor or dirty burners. You may hear a bang. See furnace ignitor replacement. |
| Gas valve | A valve that doesn’t seal fully can let a little gas through. |
| Flex connector or fittings | The short gas line into the furnace, or a joint on it, can loosen or wear. |
| Pilot light (older furnaces) | A pilot that has gone out on an older furnace or water heater can let gas escape. |
| Another gas appliance | The water heater, range or dryer near the furnace can be the real source. |
None of these are DIY fixes. Leave valves, connectors and the gas meter to the utility and a licensed technician.
Gas or carbon monoxide?
A gas leak and carbon monoxide are different dangers, and only one of them has a smell.
| What | Smell | What warns you |
|---|---|---|
| Natural gas | Rotten eggs (added odorant) | Your nose; sometimes a hiss near a gas line |
| Carbon monoxide | None | A CO alarm, or headaches and flu-like symptoms in more than one person |
A CO alarm is not a gas detector, so it won’t warn you about a gas leak. If a CO alarm goes off, the steps are the same: get out and call 911. Read more in our guide to furnace carbon monoxide safety. A sewage smell is a plumbing issue, covered in sewer smells in your house.
After the gas company leaves: getting your heat back
When the utility finds a problem with an appliance, it usually shuts off the gas to that appliance and may tag it so it isn’t used until it is repaired. PSE says it will diagnose an appliance that may not be safe, with minor repairs for a charge. Don’t turn the gas or the furnace back on yourself.
That is where we come in. Home Comfort Alliance repairs gas furnaces across the Seattle-Tacoma area:
- Dispatch fee $119; diagnostic $72 standard or $130 deeper (listed separately), and you approve an upfront price before any work begins.
- After-hours emergency heating and cooling service for qualifying emergencies, such as no heat in cold weather ($330 after-hours fee). Book by phone or online.
- Every gas repair we do ends with a carbon monoxide check before we leave.
If the problem is a gas water heater, our plumbers work Monday to Friday, 8 AM to 5 PM, with same-day service when possible. For a furnace, see furnace repair or emergency furnace repair.
The gas company found no leak, but I still smell gas
That happens. The smell may come and go with a particular appliance starting up, or the source may be outside, such as a neighbor’s line or the meter. Call the utility back if the smell returns; it is free to have PSE check. If they clear the gas system and the smell only shows up when the furnace starts, book a furnace repair visit so a technician can check the burners, ignition and gas valve while it runs.
How to prevent gas problems
- Yearly furnace tune-up. Ours checks the flue and piping, burner assemblies, gas pressures and safety controls ($230, or $180 for Home Comfort Club members). See furnace maintenance.
- Carbon monoxide alarms on every level and outside sleeping areas. We install carbon monoxide alarms; ask our electricians.
- Keep the meter and vents clear of plants, snow and stored items.
- Call 811 before you dig. The Washington State Patrol asks homeowners to call 811 at least two days before digging so buried gas lines can be marked.
Thinking about getting off gas entirely? See gas to heat pump conversion.
Gas smell FAQ
What should I do if I smell gas near my furnace?
Leave the home with everyone, including pets, without using switches, plugs or phones inside. From outside, call your gas utility (PSE 1-888-225-5773 or Cascade 888-522-1130) or 911, and stay out until they say it is safe.
Who do I call if I smell gas in Seattle or Tacoma?
Call the gas utility named on your bill, usually Puget Sound Energy at 1-888-225-5773, or 911. Cascade Natural Gas customers call 888-522-1130. Always call from outside.
Does PSE charge to check a gas leak?
PSE says it sends a technician at no charge when you report a suspected leak. Minor appliance repairs PSE makes carry a charge.
Is it normal to smell gas when the furnace turns on?
A brief whiff as burners light can happen, but you can’t tell that apart from a leak by smell. If it doesn’t clear right away, or you smell gas when nothing is lighting, leave and call the utility.
Should I open the windows if I smell gas?
Don’t stay inside to do it. Cascade advises not to open or close windows. Get out, leave the door open behind you, and let the utility ventilate the home.
Should I shut off the gas meter myself?
Leave the meter to the utility unless they tell you otherwise, and never turn it back on yourself after it has been shut off.
Can my carbon monoxide alarm detect a gas leak?
No. A CO alarm detects carbon monoxide, which has no smell. Natural gas is detected by its added rotten-egg odor. Both are reasons to leave and call for help.
What if the gas company finds no leak but I still smell gas?
Call the utility back if the smell returns. If the gas system checks out and the smell only appears when the furnace starts, book a furnace repair visit so a technician can check the burners, ignition and gas valve.
Can I use my furnace after a gas smell?
Only after the utility says it is safe and any shut-off or tagged appliance has been repaired. Don’t turn the gas or the furnace back on yourself.
What furnace problems cause a gas smell?
Delayed ignition, a gas valve that doesn’t seal, a loose or worn flex connector, and a pilot that has gone out on older equipment are the usual causes. A technician finds which one once the home is safe.
Need your furnace checked after a gas call?
Once the utility says it is safe, our NATE-certified technicians find the cause and give you an upfront price before any work begins. After-hours emergency heating and cooling service for qualifying emergencies ($330 after-hours fee).
Get an estimate
A local comfort advisor will call you to set up your visit.
Sources: PSE, detect a leak; PSE, gas safety tips; Cascade Natural Gas, emergency information; NW Natural, if you smell natural gas; Washington State Patrol, gas safety. Checked October 2026.