Warm, but not hot water

[Onroadagain]

We just spent the weekend in our 2016 30.2 Thor Ace. We plugged in at an RV park. We heated our water. The water at the faucets or shower, initially, flows hot, 2 to 3 seconds. Then the tempature drops to warm and stays warm.

We heated via electric and gas, and get same result. We leave heat switch on for several hours, even over night, with same result.

We didn't have this problem last year. The only thing different which, we think, may be causing this, is where we hooked up to city water at the RV park. It was our first time to use city water hookup.

Does anyone know what might be causing this? Thanks.

Neil

[tmshih]

RV Geeks have a video mentioning one possible cause for this.

https://www.youtube.com/watch?v=IsiXaMEneaY

Turns out they used the outdoor shower and left it shut off at the shower wand, but open for both the cold and hot faucet valves allowing the cold and hot water to mix resulting in lukewarm water

[EA37TS]

The first place to look is the water heater by pass valve. If the valve on the line between the hot and cold side is open the hot and cold will mix causing warm rather than hot water coming through the faucets. Your valves should look similar to the ones in this pic for normal use.



The valves on the hot and cold lines are in line while the one on the bypass line is perpendicular to the line.

[Onroadagain]

Thank you for your replies.

I had used the outside shower and I thought that the problem was as suggested by Tmshih. Great video by the way. Very helpful.

Turns out the solution was as suggested by dstankov. Before winter, I had opened the hot/cold water by pass valve in order to drain the hot water tank and lines. This spring, on our first use for the year, I had I forgotten to go back and close the valve. As such, the hot and and cold were mixing and I was getting warm water.

I closed it. Problem solved.

Thank you both for your time to help me.

Neil.