mypopslou Report post Posted June 4, 2015 When in a campground for several weeks I usually leave the gray tank drain valve open. Recently I noticed that my tank does not seem to be draining. I stuck a hose up past the valve so I know it is at least partially open and we have always been very careful about food particles we allow to go into the tank. We do have a new washer/dryer which we have been using a lot. I tried closing the valve and letting the water accumulate to see if additional water would flush out but when my gauge showed 2/3 full I pulled the valve and very little came out in a slow trickle. Again I tried putting a garden hose up the pipe and turned on water to see if it could dislodge anything because obviously something is clogging the drain, although not completely. Is there any type of additive I could put down the drain to help this situation or do I need to dismantle the drain to see what I can see. Would a hanger/snake up the pipe help? Any suggestions would be appreciated. Share this post Link to post Share on other sites
kaypsmith Report post Posted June 5, 2015 A clogged vent pipe can cause the symptoms that you describe. A climb to the roof might be in order, if you have more one than stack, determine which is to the gray tank, open the gray valve insert hose down the pipe and dw or someone to watch for drainage. Dirt/mud daubers, wasp, and other varments can build nest and cause these symptoms. Also a large amount of Dawn dishwashing detergent down the sink with hot water will help remove grease buildup in the system. And lint buildup from the washer could possibly be the culprit, there is a gadget on the market called the claw, inserted at the drain end might dislodge the culprit. I know that most leave their gray water open when camped with full hookup, but I keep my valve closed, then drain daily when on full hookup just for this very reason. Hope there is a simple solution for you. PS, if you use a snake from the discharge end, be prepared to get wet. Share this post Link to post Share on other sites
jleamont Report post Posted June 5, 2015 I talked to a fellow camper at a campground with this problem a few years back. He actually had a water snake climb up the sewer hose into his tank and it got stuck at the valve. Dont stick your hands in there. Ever since then I close that grey valve and drain it daily. Share this post Link to post Share on other sites
kaypsmith Report post Posted June 5, 2015 Another reason for closing the drain valve added to my list. Thanks Joe! Share this post Link to post Share on other sites
jleamont Report post Posted June 5, 2015 Kaypsmith your welcome, it was the talk of the campground, I will never forget it either. Share this post Link to post Share on other sites
wildebill308 Report post Posted June 5, 2015 Are you sure it is 2/3 full? Those gauges are notoriously in accurate. Bill Share this post Link to post Share on other sites
mypopslou Report post Posted June 22, 2015 Thanks for all of your suggestions. I used almost an entire bottle of Dawn and it did work and everything seems to be draining correctly now. I did check the vent pipe and it was clear so I knew it had to be a buildup that was causing the problem. Going forward I will be using Dawn on a regular basis just to avoid a reoccurrence.Thanks for all you helpLou Share this post Link to post Share on other sites
steve and karen Report post Posted January 7, 2016 Mine acted the same way.I found the valves were put together. My gray tank is the large valve. Share this post Link to post Share on other sites
wayne77590 Report post Posted January 10, 2016 I get confused sometimes. I don't know if it is 2/3 full or 1/3 empty. Confusion, confusion. Thanks for the Dawn info. They say never use it for washing the vehicle as it's to strong. Share this post Link to post Share on other sites
elkhartjim Report post Posted January 11, 2016 Thanks for the Dawn info. They say never use it for washing the vehicle as it's to strong. It removes the wax, Wayne. Share this post Link to post Share on other sites