Propane alarm goes off when I turn on my AC

[Carlo72]

Hello everyone. Last night our Propane alarm kept going off everytime we turned on the AC. The alarm would sound for a couple of minutes then it would turn off. Before going to bed I turned off the propane on the main tanks in the front of the RV but I was afraid to turn the AC back on. In the morning I left the propane off and turned the AC on to see if it would sound off the alarm. All seems to work okay so far. The alarm hasn’t gone off yet but I haven’t turned on the propane yet.
Can anyone tell me why this happened? I want to be able to keep both the propane and AC on without the propane alarm going off. Thank you!
I have a Keystone Cougar light 33RBI

[travelin texans]

Check your rv batteries! The LP/CO sensor is hardwired to the rv 12 volt system & will alarm if batteries are low. Why it happens with the AC is a mystery as far as I know they have nothing 12 volt in common except the thermostat.

[DVPete]

We call it a "propane" detector but it will actually detect any flammable/explosive gas (butane-propellant for spray cans, hydrogen-charging battery, methane-cows/dogs/old men, even gasses from new carpet and glues can set it off) so it may not be propane that is setting it off. It could have simply been some other gas sitting stagnant in the AC ducting that was stirred up when the AC was turned on. There is no propane directly associated with the AC system or ducting.

[JRTJH]

Your profile doesn't include the year of your RV. Most LPG detectors have a limited lifespan of 5-7 years. After that, the detector isn't reliable and may not work properly and/or may "false alarm" when there is no propane near the detector. Additionally, the coating on the detector can be contaminated and rendered inoperable if exposed to some cleaning chemicals, natural gasses (think flatulence), dirt or other substances.

You might, depending on the age of your RV, be in need of a replacement LPG detector.

[Carlo72]

Your profile doesn't include the year of your RV. Most LPG detectors have a limited lifespan of 5-7 years. After that, the detector isn't reliable and may not work properly and/or may "false alarm" when there is no propane near the detector. Additionally, the coating on the detector can be contaminated and rendered inoperable if exposed to some cleaning chemicals, natural gasses (think flatulence), dirt or other substances.

You might, depending on the age of your RV, be in need of a replacement LPG detector.
Thank you JR. It’s a 2016. I’ll add that to my profile.

[SC Dreamer]

Unless you actually do have a small propane leak somewhere and the a.c. moving air flow got it to the sensor. Leak test may be the safest thing to do.

[GHen]

Sounds like the batteries were low and when the AC kicked on the converter stopped charging long enough for to the voltage to drop again.

[sourdough]

Have you smelled propane anywhere at any time? LP sinks and the AC could be picking it up and setting off the detector. I would think you could smell it but..... The 2nd year we had this trailer I kept smelling a faint odor of LP but could not pinpoint the problem, and did not smell it in the trailer unless igniting the stove, but it was there. Had a leak test performed and the regulator had a small leak so it was replaced.....right under/next to us in the bedroom....:eek: