I have a Whirlpool 40 gal gas water heater that I got around 2 years ago.
Doing dishes tonight, I noticed the warm water was getting colder. When I went to check the water heater, the signal light which indicates proper function was off. It had been continuously on since I got it.
I first tried reigniting it following the instructions on the heater: turned the little knob to PILOT and kept clicking the igniter button once every second but the light wouldn't come on.
Then I thought that some weird little object could be stuck in between the gas pipe shutoff valve and the heater so I disconnected the yellow flex connector at the heater and confirmed that that was not the problem -- the gas flow was normal.
When I reconnected the pipe, I went ahead and tried reigniting the pilot, the same as before. This time it worked after a few tries but the heater would actually not start heating water. In other words, even though the water in it is cold (I tried releasing a few drops from the drain valve at the bottom), the flames don't light up and the heater remains cold. So I have no hot water now.
The little signal light is not powered by external electrical supply but instead there is something inside the heater that generates the low voltage out of I guess burning gas. So evidently, the pilot flame IS burning inside the heater but the burner won't come on.
What could be the reason of this malfunction?