When we arrived in Memphis we were having hot water problems. The water coming out of the tap was only lukewarm, if that. It was just warm enough to wash and do dishes with, not the steaming hot that it always had been. I turned the tank off over night to see if it would reset or something but it was the same after I turned it on again in the morning. Lukewarm.
Thinking I had a bad circuit board at best or a shot tank at worst, I looked up RV Repair on the Internet and found a mobile repair service. I called and they were here within an hour. He went through all the things I had done to no avail and then he started checking out the equipment. He figured there was nothing wrong with the tank as the water inside the tank was hot, it just was not getting to the taps.
He checked all the pipes and removed the backflow valve but that was not the problem and then he asked me if we had an outdoor shower and if I had used it recently. I did and I had! I had showers in Florida and had used the shower head to hose out the compartment in Clarksdale. He told me to go and see if I had turned the shower off by turning the taps off or by simply turning off the shower head. That was the problem! I had turned off the shower head and left both the hot and cold taps on. This was allowing the hot to mix with the cold in the pipes!
He put everything back together and gave me a bill for $160. A very expensive plumbing lesson!