I purchased a house about 7 months ago and found it had interconnected AC smoke/CO detectors that were all unplugged. Not knowing the age of them I replaced them all using photoelectric smoke/CO detectors in the basement and main floor and ionization smoke detectors in the upstairs bedrooms. All are from the same manufacturer and include voice alerts and 10-year batteries and all test good.
Just today they went off for the first time ever with a smoke alarm. Neither seeing nor smelling smoke, and possibly being stupid but not wanting to loose anything, I rushed around the house checking for smoke with extinguisher in hand and found none. I then took a closer look near each detector and found no sign of smoke or fire but did find that the detector that initially went off was in the basement. I cleared the alarm memory and ran a test with no issues.
The only thing that I can think of that set it off may have been some R-410A AC refrigerant. The AC line runs only 3 inches from the detector and my HVAC guy said a leak may be present in the line somewhere due to having to top off the AC, 2 lbs worth of refrigerant, just two months ago.
So the question is can a photoelectric smoke/CO detector detect R-410A AC refrigerant as smoke?
Also should I move the detector? It is right at the foot of the basement stairs.
Some additional information based on comments and answers given.
I put up a divider of cardboard between the AC line and the detector 2 days ago. No false alarms since. No markings have been noticed on the cardboard even though the AC has been running on and off throughout so an oil cloud is not likely. The AC has not lost any efficiency since it was filled. If it is a leak it's not a big one. The AC line has buzzed a few times so I'm going to have an HVAC company over for checks.