Big country atwood water heater leaking

Just purchased a Big Country 3850mb and the atwood water heater is leaking. It is leaking into the storage compartment area. Have tightened several fittings and the shower drain. It is now only leaking when the hot water is turned on. The wood base below the water heater is wet and small amount of water on top of the black electrical box below the hot water outlet. Have tightened both the hot and cold water. Would this be because of the check valve that I have seen in some other posts? Any help would be greatly appreciated. Everything else has been great with the camper.

Sorry to hear about your leak.

Suggestions:
1. Right away, get a fan in there to dry the wood out
2. Dry all pipes and connectors
3. Have another person turn the hot water on while you carefully observe where the leak actually is

Until you know what is leaking, it's hard to know what tackle.

When our started to leak it was the plastic inlet elbow at the bottom for the cold water. Wrap it with toilet paper to help find the leak. Once I did that found the leak right away. Our unit was still under warranty and Heartland authorized a mobile repair guy to do the repairs. They covered the bill except the service call fee. When it started our unit was only 11 months old.

Thanks for both of your responses. It ended up being the drain from the shower wasn't tight and was leaking. We are all good with that issue.

glad it was simple fix.

A lot of those screw on plastic pex fittings have a rubber gasket in them for actual seal. Over time that rubber gasket takes a "set" and begins to leak. Mine often did this with time, and temp changes. Sometimes you can tighten them, but I found, I eventually had to replace the entire fitting. Or simply buy another similar fitting and replace the internal gasket in that piece.