Every RV with propane appliances needs two different alarms: a carbon monoxide (CO) alarm and a propane (LP gas) detector. Many RVs combine them in one unit mounted low on the wall. CO has no smell, and propane only smells because suppliers add an odorant, so the alarms cover what your nose can't. Press the test button before every trip, after storage and at least once a week while you're using the RV. Replace the alarm when it reaches the end of its service life. Some common RV combination alarms are rated for five years, so check your model's manual. If the CO alarm sounds, get everyone outside into fresh air and call 911. If the propane alarm sounds or you smell gas, get everyone out, don't touch switches, shut the tank valve if it's safe, and call for help from a distance.
What RV alarms are required
NFPA 1192, the Standard on Recreational Vehicles, sets the fire and life safety rules RVs are built to. RV Industry Association members pledge to build to it as a condition of membership. The standard calls for:
- A smoke alarm listed to UL 217 and marked as suitable for RVs.
- A carbon monoxide alarm listed to UL 2034 or CSA 6.19 and marked as suitable for RV use, in every RV.
- A propane detector listed to UL 1484 and marked as suitable for RV use, in every RV with a propane appliance and an electrical system.
Each one has to be installed according to the terms of its listing. If you're replacing one, look for a unit marked for use in recreational vehicles, since that's the marking the standard asks for.
Carbon monoxide in an RV: where it comes from
The CDC says CO is in the fumes produced any time fuel burns, including in vehicles, small engines, stoves, lanterns, grills and furnaces. In an RV, that means:
- The generator, especially when its exhaust can't get away from the RV. For a portable generator at camp, the CPSC says to point the exhaust away from doors and entrances and to keep windows and vents in its path closed. The CDC says a portable generator belongs outside, more than 20 feet from windows, doors and vents. If your RV has a built-in generator, follow the RV and generator manuals for where the exhaust exits and what can block it.
- A neighbor's generator at a crowded campground, when their exhaust blows toward your windows.
- The furnace, water heater and stove (range). They're vented or meant to be used with ventilation, but a blocked vent or a fault can put CO inside. The CPSC says to clear snow away from the outside vents of fuel-burning appliances such as furnaces.
- Portable heaters, camp stoves and grills brought inside. The CDC says never to use generators, grills, camp stoves or other gasoline, propane or charcoal-burning devices inside a camper, or outside near an open window.
CO symptoms: the CDC lists headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion, and says they're often described as "flu-like." It also warns that people who are asleep, drunk or under the influence of other substances can die from CO before they have symptoms. The CPSC adds that with a fast, high-level exposure, such as a generator running in an enclosed space, people can become confused and lose muscle control without feeling milder symptoms first.
If the CO alarm sounds or anyone has these symptoms, get everyone outside into fresh air right away and call 911 or the fire department. Don't go back in until responders say it's safe, and get medical help for anyone with symptoms.
Propane in an RV: why the detector sits near the floor
Propane is heavier than air, so a leak can settle near the floor. That's why propane detectors, and combination CO and propane alarms, are mounted near the floor. Check your alarm's manual for the exact height and spacing.
Propane itself has no smell. Suppliers add an odorant so a leak smells like rotten eggs, a skunk's spray or a dead animal. The Propane Education & Research Council (PERC) warns that soil, water or rust can sometimes absorb the odorant and make a leak harder to smell. PERC also lists a cold, allergies, tobacco, alcohol, drugs, age and being asleep as things that make the smell harder to notice. So PERC says to treat a detector alarm as an emergency even if you don't smell propane, and never to ignore a propane smell even if the detector stays quiet.
If the propane alarm sounds or you smell gas
These steps follow PERC's guidance:
- No flames or sparks. Put out anything burning, and don't switch lights, fans, appliances or phones on or off inside the RV.
- Get everyone out of the RV and away from it.
- Shut off the gas at the tank or cylinder valve if it's safe to do so (clockwise to close).
- Call from a distance. Call your propane supplier, or 911 or the fire department.
- Stay out until a responder or qualified technician says it's safe.
- Have the system leak-checked by a qualified technician before using propane appliances again.
A rotten-egg smell that's clearly coming from a drain, the toilet or the black tank, with the propane alarm quiet, is more often a sewer gas problem than a propane leak. If you aren't sure which it is, treat it as propane first.
Testing, low power and replacement
- Test before each trip, after storage and weekly in use. Manuals for some common RV combination alarms give that schedule. The CPSC notes that the test button checks the alarm's circuitry, not the sensor.
- Keep the house battery charged. An alarm wired to the 12-volt house system won't work without power, and a discharged battery or a blown fuse can cut it off. Some manuals also say not to run the alarm below 7 volts DC. On some models, a repeating beep with the light flashing red and green is the malfunction signal, and the manual's first fix is to check battery voltage.
- Replace at end of life. Some common RV CO and propane alarms have a five-year sensor life and an end-of-life signal, a beep with its own light pattern. If you don't know when yours was installed, some manuals say to replace it within five years of the production date on the back of the alarm. Other models set their own dates, so check your manual and the label on yours.
- Know what can set off the propane sensor. Some manuals list acetone, alcohol, butane and gasoline among the gases the sensor can react to, so nail polish remover, alcohol-based cleaners and gas cans stored inside can trigger it. Treat every propane alarm as a leak and follow the steps above. Once the RV has been checked and aired out, look for one of these sources before you reset the alarm.
Air purifiers and CO or propane
No air purifier or odor product, AIRLOCK included, protects anyone from carbon monoxide or propane. AIRLOCK products aren't safety devices, and they don't detect, remove or reduce CO or propane. The protection is a working, in-date CO alarm and propane detector, along with good exhaust habits.
FAQ
Does my RV need a carbon monoxide detector?
Yes. NFPA 1192, the RV fire and life safety standard, calls for a CO alarm listed to UL 2034 or CSA 6.19 in every RV. Anything burning fuel nearby can put CO inside, including your generator, a neighbor's generator or a furnace with a blocked vent.
Where should a propane detector go in an RV?
Near the floor, because propane is heavier than air. Follow the height in your detector's manual.
How often should I replace my RV CO and propane alarm?
Whenever its manufacturer says. Some common RV combination alarms are rated for five years and give an end-of-life signal when they're due.
Why does my RV propane detector keep beeping?
A repeating beep can mean low 12-volt power, an end-of-life signal or a fault. Some models flash a different light pattern for each, so check the chart in your model's manual. A full alarm means get everyone out first and troubleshoot later.
What causes carbon monoxide in a camper?
Anything burning fuel: the generator (yours or a neighbor's), a furnace, water heater or range with a blocked vent, or a heater, stove or grill used inside.