Woke up to barely warm hot water this morning. The pilot light on our barely 4 year old 40 Gal AOSmith water heater was out. The pilot re-lit easy enough, and the burner fired up like it should. And about 10 seconds after it fired, the 'howling' started, as usual... ever since I installed it, the thing howls every time the burner fires, I'm assuming something to do with the rush of hot air going up the flue and heat expansion causing some vibration. Anyway, all normal. I'm on the floor looking in the window and the flame is quite yellow, and for several minutes I could hear hissing, exactly like water on a hot skillet. My first thought was the tank is leaking from the inside- BUT, there's no trace of any water ever having been in the catch tray, no calcium tracking, no water marks on the heater. I figure if the tank WAS leaking from the inside, it wouldn't just leak while the burner was on, water pressure would keep pushing it out. Also, after about 5 minutes during the reheat the hissing stopped...
So my next guess is condensation within the burner is the source of the hissing water. And it makes sense I guess, the coldest it's been in the last 4 winters has been like 15°, and right now it's brutal cold outside, got down to like 1° overnight and most of yesterday it never got above 15°, so I'm guessing the extra-cold water coming into the water heater may have caused some condensation to form within the burner, and some of it dripped onto the pilot, snuffing it out...
I'm just wondering if the condensation theory sounds plausible, and if anyone else has had something like this happen? Not sure how to deal with this other than hope it warms up outside and the pilot stays lit!
At least this heater has one of those 'pilot-on' indicators, a blue light that blinks every 3 seconds as long as the pilot is lit, and the heater is in plain view, easy enough to check during the day-