Gas odor or hissing
Treat a rotten-egg odor or hissing near a gas appliance as a possible leak. Leave without touching switches, then call 911 and the gas utility from a safe location.
Furnace emergency guidance in Frederick
What counts as a furnace emergency?
A furnace problem becomes an emergency when it may threaten people, start a fire, release fuel gas, or expose the home to carbon monoxide. A house that's simply uncomfortable still needs attention, but it usually calls for a diagnosis from us rather than a fire-department response.
The short rule
Danger to people or property means emergency action. Gas odor or hissing means leave and call 911 from a safe location. A CO alarm or possible symptoms means fresh air, then 911, right away. Smoke, flame, or sparking means leave and call 911. No heat, short cycling, unusual noise, or weak airflow without those signs usually just calls us for a timely furnace diagnosis.
Sort the call
The symptom changes the first move.
These signs don't identify the failed part. They tell you when to stop troubleshooting and get the hazard under control before calling us for furnace service.
CO alarm or symptoms
A carbon monoxide alarm, headache, dizziness, nausea, confusion, or similar symptoms means get outside and call 911. Don't go back in until responders say it's safe.
Smoke, flame, or sparks
Smoke, flame, sparking, a hot cord, scorch marks, or a persistent electrical burning odor can signal fire or electrical danger. Don't open the cabinet or keep restarting the furnace.
No heat without a danger sign
A cold house still needs timely help when pipes could freeze or someone can't safely stay cold. Without gas, CO, smoke, flame, or electrical warning signs, it's usually a call to us for diagnosis.
At a glance
Emergency action or furnace diagnosis?
No heat can be urgent without being a fire emergency. Weather, indoor conditions, freeze risk, and what your household needs still matter.
| What you notice | First action | Why HVAC can wait |
|---|---|---|
| Gas odor or hissing | Leave the home; call 911 and the gas utility from a safe location | The suspected leak must be made safe before HVAC diagnosis |
| Carbon monoxide alarm or possible symptoms | Get outside into fresh air and call 911 | The alarm source and venting need our assessment |
| Smoke, flame, sparks, or burning wiring | Leave if there's active fire or heavy smoke; call 911 | Fire and electrical hazards take priority over repair |
| No heat without a safety symptom | Make only safe observations, then call us for a furnace diagnosis | The fault may be a repair rather than an immediate life-safety event |
| Repeated ignition or breaker trips | Stop resetting it and keep the system off when safe | More attempts can worsen the fault or hide useful evidence |
Gas and carbon monoxide
Don't stay inside to troubleshoot.
If you smell the rotten-egg odor used to signal possible natural gas, hear hissing, or suspect fuel's escaping, leave without touching lights or appliances, using a phone inside the area, starting a vehicle, or creating any other spark. Washington Gas gives the same basic sequence: leave, reach a safe location, then call.
Washington Gas natural gas safety If a CO alarm sounds
Get outside into fresh air and get medical attention if anyone feels ill. Tell medical staff you suspect carbon monoxide exposure. Don't go back inside until emergency personnel say it's safe.
CPSC furnace safety guidanceOnly when the area is safe
What to tell us when you call.
For a non-emergency service call, your observations help us separate a control or airflow problem from ignition, venting, combustion, or safety-control trouble.
Leave when the air may be unsafe.
For gas odor, hissing, a CO alarm, smoke, flame, or serious symptoms, get people and pets away from the area. Don't go back for tools or to read the model plate.
Call from a safe location.
Call 911 for active fire, immediate danger, or possible CO illness. Call the gas utility for a suspected leak. Then follow their instructions.
Keep the furnace off.
Don't relight a pilot after smelling gas, open the cabinet, bypass a safety switch, test live wiring, or keep resetting a breaker to see if the problem clears.
Save useful details for us.
For a non-emergency call, note when the issue began, what the thermostat shows, whether the blower runs, what the odor smells like, and any water, soot, or fault light you can safely see.
Do not remove panels, relight a pilot after smelling gas, bypass a safety switch, or reset a breaker again and again. The CPSC advises homeowners not to install or service combustion appliances without the right knowledge, skills, and tools. That's what we're here for.
Smoke, flame, sparks, or electrical burning
Keep a furnace fault from becoming a fire problem.
A faint dusty odor on the first heat cycle can fade. A persistent burning plastic, insulation, or wiring odor is different, and it means keeping the system off until we've inspected it.
Leave active danger alone.
Smoke, flame, or visible sparking isn't a wait-and-see symptom. If there's active fire or heavy smoke, leave right now and call 911. Don't reach toward a flame, open the cabinet, or keep restarting the equipment.
Keep combustibles clear.
Keep paper, boxes, clothing, and other material away from heating equipment. The U.S. Fire Administration recommends keeping anything that can burn at least three feet from heat sources.
USFA heating fire safetyQuestions homeowners ask
Keep the safety boundary clear.
The right first step depends on what the furnace's doing and whether the home's safe.
Is a carbon monoxide alarm a furnace emergency?
Yes. Leave for fresh air, get medical help if anyone feels ill, and call 911. Don't stay inside to test the furnace or silence the alarm. It won't tell you which appliance or venting problem caused it, so leave that question for us.
Is a rotten-egg smell always a furnace emergency?
It's a possible gas leak and should be handled as one. Leave without touching switches or creating a flame, then call 911 and the gas utility from a safe location. Don't try to find the leak or relight the furnace.
Is a burning smell from a furnace always dangerous?
No. A brief dusty odor when the heat runs for the first time can fade. A strong or persistent plastic, electrical, or fuel odor, especially with smoke, sparks, a hot cord, or a breaker trip, means shut the system off if it's safe and call us for immediate inspection.
Is a furnace that will not turn on an emergency?
Not automatically. Check only simple, safe observations, like the thermostat mode and display. No heat gets more urgent once the home's becoming dangerously cold, someone vulnerable is affected, or any gas, CO, smoke, flame, or electrical warning shows up.
Need a furnace problem assessed safely?
For a safe home, tell us what changed, what the thermostat shows, and what the system is doing now. Leave first and call 911 for gas odor, a CO alarm, smoke, fire, or immediate danger.