Carbon Monoxide Detector Beeping: What Each Sound Means and What to Do in Eau Claire

Carbon Monoxide Detector Beeping: Alarm or Chirp?

A carbon monoxide detector beeping four times and then pausing is the alarm: get everyone outside and call 911 or the fire department. A single chirp that repeats about once every 30 to 60 seconds points to a low battery, a trouble signal or the end of the detector’s life. After the fire department clears the house following a real alarm, have a heating contractor check the furnace or other fuel-burning appliance before you use it again. Our directory of HVAC contractors in Eau Claire is a place to start.

Wisconsin DHS describes carbon monoxide (CO) as a poisonous gas you can’t see or smell, created when fuels like gas, kerosene, propane or wood are burned. DHS says around 500 people in Wisconsin go to the ER each year because of CO.

Sound	What it usually means	What to do
Four beeps, then a pause, repeating	CO alarm (UL 2034 four-tone pattern)	Get everyone outside, then call 911 or the fire department
A single chirp, repeating	Low battery, trouble or end-of-life signal	Check the battery, then the manual, and replace the unit if it has reached end of life

Three tones in a row is a different signal: UL 217 uses a three-tone pattern when a smoke alarm or combination smoke and CO alarm detects smoke. Patterns vary by model, so keep the manual where you can find it.

What does four beeps and a pause mean?

Four beeps and a pause means the detector is sounding its CO alarm. Under UL 2034, the signal is four spaced tones followed by a five-second silent period, repeating for at least four minutes. After four minutes the silent period may increase to 60 seconds, so four beeps with a longer gap can still be the same alarm.

Carbon Monoxide Detector Beeping in Four-Beep Bursts: Get Out First

What should I do when the alarm sounds?

Move everyone outside to fresh air, then call for help. Wisconsin DHS, CPSC, UL and NFPA agree on the steps:

1. Get everyone to fresh air right away. DHS says to move everyone outside.
2. Account for everyone with a head count.
3. Call 911 or the fire department from fresh air.
4. Stay in fresh air until emergency personnel arrive.

DHS says to take immediate action if anyone has a headache, dizziness, confusion, nausea, shortness of breath or chest pain. UL warns that some people can be exposed to dangerous levels and feel no symptoms, so feeling fine is no reason to stay inside.

Should I open windows and look for the source?

No: CPSC says not to try to find the source of the CO, and to move outside instead. UL and NFPA do count an open window or door as fresh air, but DHS says to move everyone outside.

When can I go back inside?

Go back inside only when responders say it is safe. DHS says not to go back in until the fire department has inspected and declared it safe.

What if it goes off again?

If the alarm sounds again within 24 hours after you return, repeat the same steps and call a qualified appliance technician, as CPSC and UL both advise. UL says that technician should examine your fuel-burning appliances.

Could it be a false alarm?

Yes, alarms with no CO found do happen, but CPSC and UL both say never to ignore a sounding CO alarm. NFPA’s 2023 count shows 82,245 CO incidents needing a fire department response, plus 79,051 alarm malfunctions and 79,286 activations where no CO was found. CPSC says currently marketed alarms are less prone to nuisance alarms than earlier models.

What are the symptoms of carbon monoxide poisoning?

CPSC says early symptoms of low to moderate CO poisoning resemble the flu without the fever: headache, fatigue, shortness of breath, nausea and dizziness. NFPA adds that infants, pregnant women and people with conditions like emphysema, asthma or heart disease can be more severely affected.

Who do I call in Eau Claire?

Call 911 from fresh air when the alarm sounds. NFPA suggests calling your fire department’s non-emergency number ahead of time to ask what number to call if the CO alarm sounds. For Eau Claire Fire and Rescue that number is 715-839-5013. Fire prevention and public education programs are at 715-839-4825.

Carbon Monoxide Detector Beeping Once Every 30 to 60 Seconds

Why does it chirp every 30 to 60 seconds?

A repeating single chirp is usually a low-battery, trouble or end-of-life signal. UL 2034 says the end-of-life signal repeats once every 30 to 60 seconds. On newer alarms UL says it may match other trouble signals such as low battery, and the standard allows that if a visual indicator tells them apart, so check the manual for what your model’s light means.

Will a new battery stop the chirp?

A new battery stops a low-battery chirp, but it will not stop a true end-of-life signal. NFPA says to check for low batteries and replace them if low; if the signal still sounds, call the fire department. UL 2034 ties end-of-life to the maker’s specified lifetime. The timer can only be reset for up to 72 hours at a time, and it cannot be reset after 30 days following the first end-of-life signal. When that happens, replace the detector.

Carbon Monoxide Detector Beeping and Winter CO Sources

What produces carbon monoxide in a house?

Anything that burns fuel can produce CO. DHS lists furnaces, boilers, wood stoves, fireplaces, space heaters, water heaters, clothes dryers, ranges, portable generators and idling cars in a closed garage. Poorly vented or malfunctioning appliances and leaking chimneys and furnaces increase the risk, while electric or solar-powered appliances do not produce CO.

Winter habits matter here:

• Snow: during and after a snowstorm, NFPA says to make sure vents for the dryer, furnace, stove and fireplace are clear of snow build-up. See our guide to winterizing a house.
• Cars: NFPA says to move a vehicle out of the garage immediately after starting it, and to keep the exhaust pipe clear of snow. DHS says never to run a car in an enclosed space like a garage, even with a door or window open.
• Generators: DHS says never to run a generator within 20 feet of your house. For a permanent unit, see our guide to whole house generator cost and placement.
• Heating: CPSC says never to heat your home with gas ranges, ovens or dryers.
• Fireplaces: leaking chimneys are on the DHS risk list; see our guide to chimney inspection cost.

What if I smell gas instead?

If you smell gas, get everyone out, move a safe distance away and call 911. Then call Xcel Energy at 800-895-2999 if Xcel is your gas utility. Gas is a different hazard from CO, which has no smell.

Carbon Monoxide Detector Beeping Less Often: Testing, Placement and Replacement

How often should I test it?

Test each CO alarm at least once a month, as NFPA recommends. CPSC notes that the button tests the circuitry, not the accuracy of the sensor. DHS says the start and end of daylight saving time are good moments to replace batteries and test detectors.

How long do carbon monoxide detectors last?

Plan on replacing a detector every five years or according to the manufacturer’s instructions, which is the Wisconsin DHS guidance. CPSC says alarms have a recommended replacement age from the product literature or manufacturer, and NFPA also says to follow the manufacturer’s instructions. DHS says detectors cost $20 to $50 at most hardware stores.

Where should detectors go?

Put a detector in the basement and on every floor, plus outside sleeping areas. Wisconsin law covers the basement and each floor level except the attic, garage or storage area. NFPA and CPSC add:

• Install alarms outside each sleeping area and on every level of the home.
• Interconnect them where you can.
• Follow the manufacturer’s instructions for placement and mounting height.
• Avoid kitchens and spots above fuel-burning appliances (CPSC does not recommend either).
• Keep them away from heating vents, and don’t let furniture or drapes cover them.

Carbon Monoxide Detector Beeping and Wisconsin Law

What does Wisconsin law require?

Wis. Stat. 101.647 requires the owner to install a functional CO detector in the basement and on each floor level, except the attic, garage or storage area. The law does not apply to a home with no attached garage, no fireplace and no fuel-burning appliance. The City of Eau Claire Inspections page says the requirement applies regardless of the building’s age in almost all one- and two-family dwellings that have those features.

The statute also sets these rules:

• Hardwired detectors must have a backup battery.
• Homes with a building permit issued on or after February 1, 2011, and public utility electric service, must have detectors powered by the home’s electrical wiring.
• Detectors must bear a UL listing mark, may be combined with a smoke detector, and must be installed according to the manufacturer’s directions.
• No one may tamper with, remove or disconnect a detector, or remove its batteries, except during inspection, maintenance or replacement.

Do renters have to maintain their own detectors?

Yes, the occupant maintains the detector, but a landlord has to fix one that stops working. If a tenant or an inspector gives written notice that a detector is not functional, the owner must fix it within 5 days of receiving the notice.

Carbon Monoxide Detector Beeping: When to Call a Heating Contractor

Once responders clear the house after a real alarm, get the furnace or other fuel-burning appliance checked before you use it again. CPSC says that if the source is a malfunctioning appliance, you should not operate it until it has been serviced. Our directory lists HVAC contractors in Eau Claire, and if an appliance needs replacing, see our guides to furnace replacement cost and water heater replacement cost.

Even with no alarm, schedule the yearly check. DHS says to have your furnace or wood-burning stove inspected each year by a professional. CPSC adds that the inspector should check chimneys and flues for blockages, corrosion and disconnections.