Hot Water Heater problem

[junmy3]

We have a 2005 Sunline Solaris T2553 with an Atwood hot water heater. It works on both gas and 120V. Last evening we found out that the hot water was not flowing in the camper. However it was the night before. I checked the hot water bypass valve and it was open to allow water into the water heater. Opened up the pressure relief valve on the outside of the camper and there was plenty of hot water in the water heater. Not sure what else to check. Any ideas on what I could check. Thanks

[GrandpaKip]

Gotta be another shut off valve somewhere.

[Grandpere]

Is the cold water flowing? Are you in an area that the temps are in the 20s?