RV carbon monoxide and propane alarms do not last forever, even when they seem to work. MTI Industries, which makes Safe-T-Alert, puts it plainly: replace propane and CO alarms that are over 5 years old. This guide explains where that rule comes from, how to tell the age of the alarm in your RV, and which Safe-T-Alert model to fit next.
The 5-year rule
MTI's Safe-T-Alert FAQ says to replace your propane and CO alarms that are over 5 years old, and to replace smoke alarms that are over 10 years old. MTI's dealer notice goes further: all Safe-T-Alert propane and CO alarms 5 years old and older are beyond their mandatory replacement time and must be replaced. MTI's own training material gives the service life of Safe-T-Alert CO alarms and of RV propane alarms as 5 years.
Why alarms are built to expire
According to MTI's replacement notice, Underwriters Laboratories (UL) and the Canadian Standards Association (CSA) have determined that all CO and propane alarms have a limited life. The UL 2034 and CSA carbon monoxide standards and the UL 1484 propane standard all require CO and propane alarms to be designed to stop service when their operational life has been reached. That is what the end-of-life chirp is: the alarm telling you it is done.
MTI says every Safe-T-Alert alarm is designed with a 5-year service life and includes an end-of-life warning when powered (its 62 Series CO alarm with trim ring page puts it as a signal to replace the alarm after 5 years of service), and its FAQ describes the end-of-life pattern as a beep every 25 to 30 seconds with the lights flashing red, red, green, green. See what Safe-T-Alert lights and beeps mean.
How old is the alarm in your RV?
- Check the date code on the alarm's label. MTI's testing steps start with this: replace the alarm if the date has expired.
- Look at the RV's age. If the alarm is original equipment and the RV is more than 5 years old, the alarm is past its replacement time.
- Bought a used RV? Assume the alarms are original unless you have a receipt showing otherwise.
MTI's training material also notes that RVIA has required a CO alarm in new motorized RVs since October 1993 and in all new RVs since January 1, 2005. A towable RV built before then may have a propane alarm and no CO alarm at all, which is exactly the case MTI's combination alarms are designed for.
Replace when it fails a test, too
Age is not the only trigger. MTI's safe-trip checklist says to test and inspect your propane, CO and smoke alarms every week, and to replace any propane or CO alarm that fails to test properly. The TEST button checks the electronics; MTI recommends testing the CO sensor with Safe-T-Alert CO test gas and the propane sensor with propane or butane.
Only fit an alarm listed for RV use
MTI says to install only propane and CO alarms listed for recreational vehicle use: propane alarms listed to UL 1484 RV and CO alarms listed to UL 2034 RV. Do not put a home CO alarm in an RV. MTI points out that alarms approved for RV use pass extra tests for temperature and humidity extremes, vibration, salt spray and cooking by-products, and are marked "Recreational Vehicle Carbon Monoxide Alarm", "Unconditioned Area CO Alarm" or equivalent. Every Safe-T-Alert alarm we sell runs on 12 V DC and is rated from -40°F to +158°F.
Choosing the replacement
| You have now | Fit next |
|---|---|
| A propane alarm and no CO alarm | A combination CO + propane alarm in the same spot: 25 Series, 35 Series, 45 Series or the universal 85 Series |
| Separate propane and CO alarms | Replace like for like: 20, 30 or 80 Series propane alarm plus a 62 Series CO alarm |
| An older combination alarm | Match the size with the replacement chart or use the 85 Series with trim ring |
| A Safe-T-Alert 70-742-R-KIT (alarm with valve control) | The 25-742-R kit with relay, trim ring and solenoid valve (MTI's listed alternate). For a CCI Controls alarm with a valve, MTI says to replace the alarm and valve together with its 35-742-R-KIT; send us a photo first. |
Write the install date on the alarm or in your maintenance log so you know when the next one is due.
Frequently asked questions
How long does an RV CO detector last?
For Safe-T-Alert, MTI gives a 5-year service life and says to replace CO and propane alarms that are over 5 years old.
Does the propane alarm expire too?
Yes. MTI applies the same 5-year rule to propane alarms.
When did RVs start needing CO alarms?
Per MTI's training material, RVIA has required a CO alarm in new motorized RVs (Class A, B and C) since October 1993 and in all new RVs since January 1, 2005.
Can I use a battery CO alarm from a hardware store?
MTI says never to install a residential CO alarm in an RV. Use one listed to UL 2034 for RV use.
Every Safe-T-Alert alarm we sell ships from our warehouse in Upland, California. Not sure which one replaces yours? Send us a photo of the old alarm and its label before you order and we will match it. Browse the full Safe-T-Alert range.