water heater pilot light won't stay lit

mike12345

My wife and I own a hair salon. 2 years ago when we rented the building the owner had a new AO Smith water heater put in. Worked fine until about two months ago when the pilot light started failing to stay lit (this occured just after hurricane sandy, not sure thats relevant or not). I had a plumber come in and look at it and he replaced some parts( i believe the burner assembly?). this did not fix the problem. Ultimately he was able to get a new water heater under warranty. This was installed( in a new location as he felt the issue might have something to do with flue being vented with the furnace and getting blow back, he also mentioned something about seals at the top of the water heater being slightly melted?) Unfortunately same issue! My plumber felt there is an issue with the chimney.  I contacted the landlord and had his plumber come who told me there is nothing wrong with the chimney. I work with my plumber alot as I am a carpenter and believe he is very capable. I came across this website and thought I might just ask if anyone has any ideas as it seems there are an awful lot of knowledgeable folks here.

Thanks,

Mike

unclejohn

Do you have a

Exhaust fan running to remove odors from the hair chemicals? That may cause a negative pressure in the building. Does it vent into a metal flue or a masonry chimney? If its masonry pull the flue out and look in. Also is the water heater residential or commercial? Sounds like its res. if it has a standing pilot I was thinking the air vents were clogged but replacing the heater would have fixed that.

Steve Whitbeck

flame arrestor

The flame arrestor built into the bottom of the water heater under the burner is dirty.

Normally the service man removes the burner and using compressed air he blows down through the flame arrestor to clean it. this is a common problem with AO SMITH water heaters. I have a customer with a Bradford White unit side by side with an A O Smith. AO needs to be cleaned regularly.