Carbon monoxide alarm calls: The first minute
The call that is not a service call
Most HVAC calls are about comfort. A carbon monoxide alarm call is about whether the people in the house are breathing safe air, and nobody on the phone can know. The CDC counts more than 400 Americans who die each year from unintentional carbon monoxide poisoning not linked to fires, more than 100,000 emergency department visits, and more than 14,000 hospitalizations. The symptoms it lists (headache, dizziness, weakness, upset stomach, confusion) look like the flu, so a caller who feels "a little off" is not a reason to relax.
These calls cluster in heating season, because fuel-burning heating equipment is one of the household sources NFPA names. Every caller gets the same first minute.
The first sentence, word for word
The public guidance agrees. The CPSC says to get outside to fresh air immediately, then call 911. NFPA's tip sheet says to move to fresh air, account for everyone, call for help from there, and stay out until emergency personnel say it is safe to go back in.
So intake opens with that instruction, before a name, an address, or a membership lookup:
"Please get everyone out of the house now."
"Once you are outside, call 911 or your fire department. If you also smell gas, call your gas utility's emergency line from outside as well."
"Do not go back in until the fire department tells you it is safe."
Only after the caller confirms they are outside does the call move on. The safety instruction comes before the booking, every time, on every line.
What the desk must never say
The dangerous sentence here is a reassuring one. "It's probably the battery." "If nobody feels sick, you're fine." Each is a judgment that the house is safe, and nobody on the phone is qualified to make it, whether the voice is a CSR, an answering service operator, or an AI agent.
The script forbids three things: Saying the home is safe to stay in, troubleshooting the alarm or furnace while people are inside, and suggesting the system be turned back on. If the caller pushes back ("it went quiet, can we go back in?"), the answer repeats the instruction. An alarm that has stopped is not an all-clear. The fire department decides when people go back in.
One nuance comes from NFPA itself: A CO alarm has a separate low-battery trouble signal. If the caller is certain it is that chirp, NFPA says to replace the battery and call the fire department if it keeps sounding. Anything short of certain is the alarm.
Why this call cannot become a callback
A voicemail, a message pad, or "someone will call you back within the hour" fails this caller in the only minute that matters. An answering service that takes a message and pages the on-call tech has delayed the one instruction the caller needed, and the return call may reach a family still inside.
Faster callbacks do not fix that. Speaking the instruction on the first ring does, followed by a handoff to the on-call technician or a manager with the address, who is in the house, and whether the fire department has been called, so nobody asks the caller to repeat the story outside in the cold.
Booking the inspection after the all-clear
Once responders have cleared the house, the household needs a qualified technician to inspect the furnace, venting, and other fuel-burning equipment before the system runs again. NFPA already recommends that inspection every year before cold weather. After an alarm, it stops being optional.
The booking is a normal one with three extra fields: When the fire department or utility cleared the home, whether they shut off or tagged an appliance, and whether the household has heat in the meantime. A tagged furnace in January is also a no-heat call, and your no-heat dispositions apply from there.
Stage | Intake does | Intake never does |
|---|---|---|
First 30 seconds | Tells everyone to get outside, call 911 or the fire department, and call the gas utility if there is a gas smell | Asks for an account number first |
Caller is outside | Captures address, who is in the house, reported symptoms, whether 911 was called | Judges whether the symptoms are serious |
Handoff | Transfers to the on-call tech or manager with that context | Promises a time to go back inside |
After the all-clear | Books the inspection and notes any tagged appliance | Tells the caller to restart the furnace |
The same answer at 2 AM and 2 PM
The risk on this call is drift. A seasoned daytime dispatcher gets the order right. The weekend fill-in or the CSR in week two may ask for the address first or say something softer, and either can be the one who picks up.
A written script fixes the order of what gets said, and an AI agent built on that script says it the same way on every call. Revin is custom-trained on your own call recordings and your safety script, speaks the instruction first, transfers to your on-call team with full context, and books the follow-up inspection into ServiceTitan once the home is cleared. A dedicated forward-deployed engineer builds and tests that branch with you. It never tells a caller the house is safe, because that decision belongs to the fire department. Your CSRs keep the judgment calls.
What should you do if a CO alarm goes off?
Get everyone out to fresh air immediately, then call 911 or the fire department from outside. NFPA advises making sure everyone is accounted for and staying outside until emergency personnel say it is safe to go back in. If you also smell gas, call your gas utility's emergency line from outside as well. Do not try to find the source yourself, and do not restart the furnace.
Should I call 911 if my CO detector goes off?
Yes. The CPSC's guidance for suspected carbon monoxide poisoning is to get outside to fresh air first and then call 911. Fire departments handle these calls routinely: NFPA reported that U.S. fire departments responded to an estimated 80,100 non-fire carbon monoxide incidents in 2010, about nine an hour. Make the call from outside, not from inside the house.
Can a furnace cause carbon monoxide in a house?
Yes. Carbon monoxide forms when fuel burns incompletely, and NFPA lists fuel-burning heating equipment among the household sources. That is why NFPA recommends a professional inspection of furnaces and other fuel-burning heating equipment every year before cold weather. After an alarm, have a qualified technician inspect the furnace and its venting before the system runs again, even if responders found nothing alarming.
Can I go back inside after the CO alarm stops?
Not on your own judgment. A silent alarm does not prove the air is clear. NFPA's guidance is to stay at a fresh-air location until emergency personnel declare that it is safe to reenter the home. After that, keep the heating equipment off until a qualified technician has inspected it, and ask the responders whether they shut off or tagged any appliance before they left.
How do HVAC companies handle carbon monoxide calls?
A well-run desk gives the safety instruction before anything else: Get outside, call 911 or the fire department, and call the gas utility if there is a gas smell. It never judges whether the home is safe. Once the caller is outside, it captures the address and situation, hands off to the on-call technician or manager, and books the furnace inspection after responders clear the home.
About Revin
Make every CO call start the same
Revin answers every HVAC call with your own safety script first, hands urgent calls to your team with full context, and books the follow-up visit into ServiceTitan.
