How to Check if Your Carbon Monoxide Detector Is Expired

[fusion_dropcap boxed="yes" boxed_radius="0" class="fusion-content-tb-dropcap"]H[/fusion_dropcap]ave you heard random beeps from your carbon monoxide device? Are your carbon monoxide detectors working? Can you recall the last time you’ve had it checked?

Carbon monoxide (CO) poisoning is life-threatening. Neglecting the maintenance of your carbon monoxide devices can harm the people in your property!

According to the Center for Disease Control and Prevention (CDC), accidental CO poisoning has claimed the lives of 430 U.S. residents every year.

In addition, an estimated 50,000 U.S. residents are admitted to an emergency department because of carbon monoxide poisoning complications.

Carbon monoxide detectors must be installed to act as the first line of defense against the unseen threat of carbon monoxide to ensure the safety of your home and property.

Regularly maintaining CO detectors is an essential responsibility of a homeowner or a commercial building owner.

Wondering do carbon monoxide detectors expire or how long do carbon monoxide detectors last? This guide shows you how to find the carbon monoxide detector expiration date, where the expiration date is, manufacture date vs expiration date, and what beeping every 30 seconds means. It also covers whether they go bad, how long they last, and how long are carbon monoxide detectors good for..

CO detectors may be classified according to the mechanism of operation.

The three types are as follows:

• Biomimetic sensors work when high-concentrations of the gas block the laser inside before triggering the alarm,
• Metal Oxide Semiconductors (MOS) rely on the change of temperature between carbon monoxide gas interaction to a preheated semiconductor. The temperature change is proportional to the change of resistance, which triggers the alarm, and
• Electromechanical detectors operate when the interaction of air and carbon monoxide generates an electric current. When the current goes beyond the threshold, the alarm is set off.

As for the area of installation, there are also 3 classifications to choose from:

• A combination of a combustible gas/CO detector is usually used for areas that receive heating from natural gas space heaters.
• Digital display detectors are wall-mounted devices for household installation. They are installed within the eye-level because of the display.
• Non-digital wall-mounted detectors are installed 15 inches below the ceiling to detect carbon monoxide on high levels.

In addition to sensing method and placement, detectors come in different power options: hardwired, battery-powered, plug-in, and combination smoke/CO units. Homeowners often ask whether plug-in models expire—yes, all types, including plug-in and hardwired units, have a limited carbon monoxide detector lifespan.

Note: CO vs CO2 detector refers to different gases. A CO detector is for carbon monoxide, whereas a CO2 detector measures carbon dioxide; choose the device intended for CO safety.

Just like any device run by an electrical circuit, carbon monoxide detectors expire when the sensitivity of the sensor’s components dulls because of exposure to the gas over time. Many people ask, “do carbon monoxide detectors expire?” and “do carbon monoxide detectors go bad?” The answer is yes—sensors gradually lose accuracy.

The estimated time frame is usually five to seven years, but newly manufactured models can reach up to 10 years. If you are wondering how long they last or how long are carbon monoxide detectors good for, check your model’s documentation to confirm the exact range.

Moreover, all detectors manufactured before 2013 should probably reach expiration by now.

If you’re a homeowner planning to install one, it would be easy to monitor its effectiveness by checking the expiry date behind. When renting a space with an existing device, you may not know its history; it’s best to ask the establishment owner to avoid a potential safety hazard. This also applies to plug-in, battery-powered, hardwired, and combination smoke/co units.

Many homeowners ask how long does a carbon monoxide detector lasts or how long do CO detectors last. Most carbon monoxide detectors, including plug-in units, are expected to work for about 5 to 10 years. If you are wondering how long does a plug-in carbon monoxide detector last, the answer is usually in the same range, but you should always confirm the exact timeframe on the label or in the manual.

People also ask why do carbon monoxide detectors expire. Over time, the internal sensors lose sensitivity, especially after exposure to carbon monoxide; therefore, the device can no longer accurately read CO levels and must be replaced.

To verify these, manufacturers print a manufacture date and expiration date on the back of the detector. If you’re comparing manufacture date vs expiration date, the manufacture date tells you when it was made, while the carbon monoxide detector expiration date tells you when to replace it. If you’re unsure where the expiration date is, check the back or inside the battery compartment door.

From 2009 to 2013, federal laws required many homes and commercial buildings to install CO detectors. That means many of those early devices are already expired or are very close to expiring now, making inspection an urgent matter. If you have an old carbon monoxide detector, consider replacing it proactively.

If you notice that your detector is at or past its expiration date, or is about to expire soon, schedule an appointment with a fire prevention specialist or a licensed electrician to replace it with a new, reliable carbon monoxide detector.

Aside from the expiration date, manufacturers also integrated warning signals to notify owners of the device’s expiration. These are common signs your CO detector is expired.

For detectors with digital alarms, the screen will show an “ERR” or “END” message, which means the device is up for disposal. We explain what beeping every 30 seconds means. You will hear a “beeping” or “chirping” sound every 30 seconds, a signal that you should have it replaced.

Be mindful of the sound pattern when it rings. Most detectors signify when it detects high carbon monoxide concentrations through a different tone.

Intermittent beeping every 4 to 5 seconds alerts a carbon monoxide leak, which means you need to call the fire department.

On the other hand, carbon monoxide detectors that are non-digital exclusively flash a red light with the beeping sound on a 30-second interval when the battery is drained.

The emitted signals should stop by replacing the batteries with new ones, and the device is ready to work again. If the signals persist even after the battery replacement, your device has reached its end-of-life.

It is important to remember these indicators and immediately replace your carbon monoxide alarm to prevent CO poisoning.

It’s also good practice to manually test the functionality of your device.

Carbon monoxide (CO) detectors have an integrated “test” button on the back or front of the device.

Make sure to test monthly to evaluate the device’s performance and maintain its effectiveness.

To test your detector, follow these steps:

1. Press the “test” button and wait for two beeps.
2. If you don’t hear any sound or if the alarm is inaudible, replace the batteries.
3. When the batteries are all new, but the sound is still non-existent, replace your detector.

For monitored detector installations, inform your provider beforehand to avoid triggering the emergency alarm. For hardwired systems, follow the manufacturer’s testing instructions and silence procedures.

It is also good practice to involve family members when testing the device. Assign them to certain places at home to check if the alarm is audible.

To ensure that the testing is professionally handled, hire a fire protection company to assess your device.

On average, the cost of a residential electrical inspection in Arizona can range from $275 to $350, but prices can be higher or lower depending on the size of the home, the complexity of the electrical system, and the expertise of the electrician doing the inspection.

It is your responsibility to protect your family members from the dangers of carbon monoxide poisoning by installing a detector and making sure it is fully functional.

Exposure to high concentrations of CO can lead to severe consequences.

If unsure as to what you should do, you can seek the help of professionals.

Assurance Electrical Services in Prescott, AZ’s, is your hometown electrician ready to cater to your electrical safety needs with integrity and accountability.

Do you have any questions regarding your carbon monoxide detector installation? Have you recently discovered that your device is expired?

Frequently Asked Questions

1.Do carbon monoxide detectors expire, and how long do they last?

Yes. All CO detectors—including plug-in, battery-powered, hardwired, and combo smoke/CO units—have a limited lifespan because their sensors lose sensitivity over time. Most last about 5–7 years; newer models may be rated up to 10 years. Detectors made before 2013 are likely already expired. Always confirm your model’s exact lifespan in its documentation or on the label.

2. How do I find the expiration date, and what’s the difference between the manufacture date and expiration date?

Look on the back of the detector or inside the battery compartment door. Manufacturers typically print both a manufacture date (when the device was made) and an expiration or “replace by” date (when the unit should be replaced). Use the expiration date to know when to swap the unit, regardless of whether it still seems to work.

3. What does beeping every 30 seconds mean, and how is it different from other alert patterns?

A chirp about every 30 seconds usually signals end-of-life or a low battery. Digital models may display “ERR” or “END” to indicate the unit should be replaced. Non-digital units may flash a red light along with the 30-second chirp when the battery is drained; if new batteries don’t stop the signal, the detector has reached end-of-life. By contrast, rapid beeping every 4–5 seconds indicates a dangerous CO level—treat that as an emergency and contact the fire department.

4. How often should I test my CO detector, and what steps should I follow?

Test monthly. Press the test button and listen for two beeps. If you don’t hear a clear alarm, replace the batteries; if it’s still silent (or weak) with fresh batteries, replace the detector. For monitored or hardwired systems, notify your provider first and follow the manufacturer’s testing/silencing instructions. During tests, have family members listen from different rooms to confirm the alarm is audible.

5. Does the power type or placement change whether a detector expires, and where should I install different types?

Power type doesn’t change the fact that all detectors expire—plug-in, battery-powered, and hardwired units all have limited lifespans. Placement varies by model: digital display units are typically wall-mounted at eye level; non-digital wall-mounted units are often installed about 15 inches below the ceiling; and combination combustible gas/CO units are common in areas heated by natural-gas space heaters. Also note: CO and CO2 detectors are different—use a CO detector specifically for carbon monoxide safety.