In November I replaced a water heater that leaked, with a 30 gallon natural gas GE from Home depot.

A few months later the pilot started to go out every few days. I replaced the water heater again, same model. The new one had the same problem, so GE had a plumber come and replaced the thermo coupler and pilot system and the gas valve. The water heater is located in the furnace room. There are no other appliances in the room, there are no windows in the room. There is no condensation anywhere in room or on unit.

It worked well for a week, but is happening again. I had the gas co come check the pressure and static and flow above 9. The Water heater vents to the chimney as does my furnace, I had the venting checked and the chimney is super clean. I am baffled at this point and beyond frustrated. I live on the East Coast In Boston area. Furnace is not running as it's July. There is a cap on Chimney.

I have no clue where to go from here. Any ideas??