Problem Draining Fresh Water Tank
I have a 1996 Roadtrek 190, have had it for six years, and am the third owner. Ever since I've had it, the tank draining has been a puzzle. I've taken the cap off the drain line and the water barely trickles out. This year, the water pump started acting up. I figured it was 16 years old, so I'd just replace it. The results were about the same. Initially when turning on the pump, water would flow, but quickly fizzle out.
Now, when trying to winterize, I finally got my lazy butt underneath the vehicle (with the aid of some blocks) and saw that there is one line coming from the tank. It "T's" off to the water pump, then continues to allow draining under the driver's seat. I discovered there is a filter-- a disc about 1-1/2 inches across-- attached to the tank and then the fresh water line is attached to that. Upon removing the filter, the water flowed freely from the tank onto the ground and I moved freely to get the heck out of the growing puddle! The filter itself had a thick layer of gunky growth. I was able to clean that off, but apparently that has been the issue all these years. I'm certain the inside of the tank is not pretty, either. I put it back together for now to enable winterizing, but in the spring I plan to take the filter and line off again and try to chlorinate and flush the tank out as best I can through the manual fill- leaving the plumbing lines out of it.
I'm somewhat embarrassed to relate this tale, but I hope it will help someone else out who wonders why the water flow from the manual drain line is poor to non-existent. I don't use my van too often, and I have tried to keep either no water or "treated" water in it during the summer. I may have bought the gunk, but I may also be at fault. But lesson learned that I wish to impart to you is that the water tank can get nasty very easily and that manual draining and water-pump function can be stymied by slime in the tank-mounted filter.