I have a 2010 16' that we just purchased.

As we're working through getting it cleaned up flushing the water system, it had been in storage for the last 3-4 years, hot water does not flow from the kitchen faucet or shower.  When we bought it and towed it home I noticed that water and wet paper looking debris was coming out of the external drain plug on the hot water tank.   Yes it was off when we were driving. I've tried flushing the system and did some reading on the Atwood hot water heaters.  Online people are reporting that the check valve on them can plug up on the hot water exit.  I removed the the 90 deg fitting to find that it is not a check valve but with that off and with a cleaning wand I started to run a lot of water through the tank with the drain open..,   I'm getting a lot of debris from the drain, it looks like wet pieces of paper, some clear to grey slime.   While i had the hot water line off the tank I've blown out the faucet and shower lines with my air compressor and will flush them out with fresh water before I hook the line back up to the tank.

I would love to hear your thoughts on cleaning out the tank so we can start using it.     the one thing I can't confirm is if the cold water supply line has a check valve on it.   Does anyone know if scamp plumbs their water systems with check valves?   

thanks for the read looking forward to your thoughts...