I purchased an AO Smith propane hot eater heater two yrs ago. The flammable vapor detector has locked up numerous times forcing me to call a plumber.The plumber and myself called AO Smith for the lockout code to reset, AO Smith insisted that I must be storing a flammable vapor in my bsmt. After numerous checks with a portable flammable vapor detector no vapors were detected. AO Smith asked if my bsmt had any moisture as this could set off the detector when I stated that my bsmt was dry I was told that water the chemical component being H2O contained hydrogen and that you remember what happened when the Hindenberg Exploded in New Jersey and that hydrogen was the vapor therefore water is a flammable vapor.
This is a true story AO Smith Customer Service never returned my calls. I subsequently installed an electric Hot water heater.
I spent 17 yrs as an Arson Investigator for the NYC Fire Dept. Water is not a flammable vapor.
Anyone have any idea on how to deal with AO Smith,