Recently, I notice that the back up tank (gas) is burning every time hot water is used. Usually, the back up tank never burn in summer (these couple weeks we are between 90 to 100 degrees). I looked at the solar controller and see that only the power light is on. The output light is not. Usually, the output light is on when there is sun (noon).
Touching the piping, this is how I see.
1- Input pipe is not hot.
2- pipe goes up to the solar panel on the roof is extremely hot.
3- Pipe coming down from solar panel to the tank is extremely hot.
4- Out put pipe from tank is not hot at all.
Anyone know if the controller is definitely bad, or the sensors, or it's something else in the tank? After some searching/reading, I know there is are 2 sensors somewhere and the tank also has the pump somewhere but I don't know anything else.
This is a of the same controller I found on the internet
