Dear Dave,
I just read your article on propane safety and I have a question. The propane detector in our 5th wheel is 3 years old and it beeps when we are traveling, never when we are stationary or camping. When I hit the cancel button, it stops. Could the exhaust from the truck be causing the alarm to sound? —Deborah, fifth wheel
Dear Deborah,
You did not provide the make and model of your 5th wheel; however, most use a very common liquid propane (LP) leak detector. Most are located in the kitchen or lounge area close to the floor, as LP vapors are heavier than air and settle to the bottom.
Example of LP leak detector
Here is a photo of a unit in a 5th wheel at the NCRVDA Show in Raleigh in 2024. It is a Safe-T-Alert, which should be similar to the model you have. It is powered by a 12-volt source and typically wired to the 12-volt DC side of the distribution panel, which gets power from the house battery.
According to the specifications, these are fairly sensitive, with a reading of 4200 parts per million (ppm). So it could very likely be the exhaust setting it off. However, your rig should be sealed up in such a way the exhaust is not getting inside the rig. If it is, I would be worried about the inside filling up with dangerous carbon monoxide!
I have heard stories for years from customers that stated their detector would go off when air freshener was sprayed anywhere in the rig. Some said perfume or aftershave, and several said it would go off when their dog farted! (I think I might get a new dog.)
Usual cause of detector going off
Usually the issue I have found with these is the low battery warning that sets them off. Several years ago, units would sit at the dealer lots. Since they were not plugged in, the battery would drain, as these draw about 1.5 amps. In no time, they would start beeping. You would walk around the lot and a dozen or more were “chirping”—it was quite annoying. Many dealers took them out. Then RV manufacturers started installing 100W solar panels, which were just large enough to keep up with the LP detector.
I just had a similar situation with a Winnebago View in storage near my office. The unit would trip the GFCI circuit breaker now required in storage facilities, and the LP detector would not stop beeping. We found the batteries were bad and the converter had just enough voltage leak to trip the breaker and set off the detector. I called Winnebago and found that the detectors were very weak after about 5 years. I was told to replace it and use a trickle charger instead of the converter. We also replaced the batteries and it worked.
It is very possible your rig is drawing more power than the tow vehicle’s alternator can provide, especially if you have lithium batteries. In this case, you might need a DC to DC charger.
A test to try to identify cause of LP leak detector going off
A simple test would be to run the unit down the road until the detector starts beeping, then pull into a parking lot and let it idle. If the detector continues to beep, it’s most likely low batteries, as you then would not be getting exhaust from the tow vehicle. You should also be able to use a multi-meter to determine what the batteries are reading.
When you plug into a campground source, the converter will be providing a full 13.2 volts or more, so that would be enough to keep the detector from beeping.
If it is a low battery issue, you could try a 100W solar panel or a DC to DC charger. I might also recommend a new detector, as they are fairly cheap on Amazon here.
You might also enjoy these posts from Dave
- Essential LP cylinder safety tips
- Readers’ comments on refillable LP cylinders and legality of transporting them
- The ultimate guide to liquid propane (LP) systems
- How do I know when my LP tank is at 80 percent?
- I’m told my LP tank needs recertification so can’t be filled, but I’m getting conflicting advice
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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The 7 pin connector supplies 12 volts to the trailer while the vehicle is running.
It charges the battery and supplies power to run things like lights, refrigerator (if it runs on 12 volts), the brakes and jack. The plug supplies at least 15 amps, more than a 100 watt solar panel, and more than enough to supply the detector.
I like the dog farts setting it off, my dog has been known to rip a good one now and then but he’s never set the propane detector off.
But you’re not laying on the floor!
Thank you for the trouble-shooting information, Dave! I suppose they can learn that the sensor went off while traveling if it isn’t alarming when they close the RV to travel and it is alarming when they reach their destination. With no one legally inside the RV while towing, how will they know when the sensor goes off? Leave a cell phone with an open connection inside the RV? Was there a particular way you had in mind? Interesting problem. Have a great day and safe travels!
The other thing people could do is look at the sensor when it is beeping. There are lights on it and blink, telling you what the issue is (right beside the light is a description of the codes).