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Old 02-23-2019, 05:52 PM   #1
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Join Date: Feb 2019
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Grey water tanks

Hi I am new to this site and am looking for some help on grey water tanks on a 2012 Sunseeker 3120DS Class C motorhome. I recently purchased this unit from an RV lot with not much help from them. Took our 1st trip on the road and then connected up and tried to take a shower and water started o back up in the shower. The grey water dump valve would only trickle out, so I knew I had a problem my friend and I opened up the dump valve to get a snake in and found out a rodent had gained access and to the drain line on the grey line and had packed the line full of acorns. Finally got them cleared out and the grey water runs out full blast. Problem fixed I thought But when I tried to fill the tank and sanitize according to the capacity on the grey tank it is one grey tank at 39 gal. & one Black tank at 39 gal. after pouring 20 gallons to refill the water backs up into the shower and cannot hold 39 gallons. Am I missing another dump valve ? I can only find 2 valves at the sewer connection is there another valve on this model that I cannot find? Please Help

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Old 02-23-2019, 06:46 PM   #2
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Location: Mount Laurel, New Jersey
Posts: 9,181
Looks like there is a nest/more nuts in the tank. Maybe take the valve out and push a running garden hose in there and try to flush everything out. Make sure if you do that to have the back of the RV higher then the front to help get the junk out.

2012 SunSeeker 3100SS Toad-1962 Futura Average 100 + days camping
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Old 02-27-2019, 01:42 PM   #3
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Grey water tank

I wanted to thank you for your quick response to my post. I took ,advice and pulled the whole connection and valves to the 3in & 1 1/2 in previous plugged line, raised up the rear of the motorhome and tilted the tanks to the connection poured 5 gal of water into shower then bath sink and kit sink all drained out with no restriction. I ran a snake up grey line had no restriction and tapped tank sounded empty then ran a lot of water through pipes and no more debris came out. It still seems as though there is another grey valve I am missing. Looked under unit still cannot find one. Don't know where to go from here
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