Hi Bill, unfortunately, I'm not really sure of the maintenance of the unit as we had just bought it from a dealer "as is" and were on our first camping trip with it. We just noticed some water under the kitchen sink floor, it wasn't until we got home and further checked it out. We had checked all of the plumbing once we had pressurized the system and eliminated the pipes. That's when we had seen the leak coming from the water heater, on the inside of the cabinet, underneath towards the front. Upon inspecting it, there was a lot of rust in that area. I had taken the anode rod out at that point and it was pretty much not there, my suspicions are it had not been changed in a long time. The trailer is from the northeast, it is a possibility it had not been drained properly also and it may have frozen.
The good news is that it is in my possession now and all maintenance and care are being done by me.
Tex