Grey tank stopped up won't drain

My galley tank did that last summer. Just trickled out so I put a bunch of tank cleaner in it and drove to the next camp ground and it worked find after that, so it must have had a grease plug in it.

you probably already know this but just because you close you close the valve doesn't mean you have to remove the sewer hose. Just trying to keep it simple.
Live long and prosper!

Sounds to me like you found out why most people are recommending leaving the valves closed and only opening them when almost full. I am sure your setup has never failed you in 4 years but now it has. Is there any particular reason you have against leaving the valves closed?

There are some things I just take people at their word. When I started full timing, messing with waste was something I didn't want to experience any mistakes first hand.

DAWN...full big bottle of DAWN dishwashing liquid + full tank of water + leave alone for a couple days. Then open the valve. Worked for me on a plugged black tank.

And if you have a better tank cleaning method to share, I'm sure the OP is wide open to good suggestions, since they are a little backed up now!

SDcampowneroperator wrote:

Grit dog wrote:
Take the camper somewhere out in a field, open the gray valve and snake the line. Stand off to the side!

Depending on how much grease you’ve dumped down the sink over the years, could be a good layer of grease in the whole tank, like as tall as the drain pipe?
I’d go after the remaining grease probably 1 of 2 ways.
1. Figure out how to get a large quantity of boiling hot water into the tank. Quick drive to slosh it around. Drain in that field again.
2. Couple gallons of something like Zep industrial cleaner/ degreaser dumped into an empty tank. Drive to slosh, drain into a sewer preferably.

. Do not do this,
That field is ours or someones, land! or an absorption sewer system biologically destroyed with the in flux of grease and solvent. Please No Do Not Do It! in a small wastewater system.
If grease is the cause of your problem do the treatment at a municipal plant that has the bugs to eat it.

Oh my gosh. Please look at the potential environmental impact of what you're commenting about. Then think about the millions of people, septics, sewers, overflowing grease traps in every city, (likely) thousands of gallons of fuel spilled daily, etc etc.
No one is suggesting making a public dump for all to use in your back pasture. And please don't insinuate the "what if every one did this" argument because this is 100% not the case.
1. It was a suggestion.
2. This is so micro minuscule in the big picture it's indiscernible.
3. Where do you think all the gray water goes from every campground and home septic/sewer system? Same place just starts out a couple feet underground.

Ever dump some bacon grease off the back porch instead of down the drain? Ever clean a shop floor with some degreaser and rinse it out? Well if you haven't, millions do. What happens if you dump that grease in your garbage can and it goes to an old landfill or dump? Is that better, or is it out of sight, out of mind.
Merry Christmas!

My bet is some solids have migrated down the drain line and are blocking the gray line. Especialy if the grey connects to the main 3" line in an elbow.

Lotion rich body soaps will build up along with hair and cause clogs. We have used "septic safe" drain cleaners when we had slow drains and the plumbing in our rig is the same as a house. We do make sure there is some water in the grey tank to start with and then after running the hot water in the drain as instructed, we do a dump. Only had that black tank refuse to drain 1 time and learned to use plenty of water when flushing after that. It was a toilet paper jam up. Didn't use enough water for the tp to break down. We also always leave the valves closed until the tanks are full and usually have to do 2 grey in between doing the black. It's not good to dump when the tanks don'g really have much in them. You don't get the water pressure from in the tank to push things out. We are full-timers also and other than the problem in the 1st year 7 yrs ago - no problem since.

Grit dog wrote:
Take the camper somewhere out in a field, open the gray valve and snake the line. Stand off to the side!

Depending on how much grease you’ve dumped down the sink over the years, could be a good layer of grease in the whole tank, like as tall as the drain pipe?
I’d go after the remaining grease probably 1 of 2 ways.
1. Figure out how to get a large quantity of boiling hot water into the tank. Quick drive to slosh it around. Drain in that field again.
2. Couple gallons of something like Zep industrial cleaner/ degreaser dumped into an empty tank. Drive to slosh, drain into a sewer preferably.

. Do not do this,
That field is ours or someones, land! or an absorption sewer system biologically destroyed with the in flux of grease and solvent. Please No Do Not Do It! in a small wastewater system.
If grease is the cause of your problem do the treatment at a municipal plant that has the bugs to eat it.

Rid X or equivalent should clear a gray water tank with no problem - but it might take a while depending on weather. I use it every few years during warm weather and apply it to gray/black tanks and let it sit a week - seems to purge everything. If gray water blockage is due to grease then warm water and dawn liquid might be a quicker solution.