Grey tank

[Davecarol]

So out for the 1st time and on the 2nd last day i stopped the grey tank from flushing as i used it to clean out the sewer hose. Now it was time to empty the day we left and all was good except my grey tank took for ever to empty. Does anyone know why?

[Jagiven]

The output pipe diameter is a lot smaller than the black tank. I use to try to fully drain the tank, now I try to leave a few gallons of water in the tank, to keep the tank bacteria health. This keeps the odors down.

[01tundra]

Our grey water tank takes forever to drain as well, the drain line is much smaller than the drain hose connection.

Ours was so slow that I ran a snake camera up the pipe to make sure there was no obstructions. I did find the worst glue job I've ever seen, but I don't think that is the problem. I wish they would've kept the drain pipe 3" the entire way.......looks like another mod on my neverending list.....

[norty1]

I have never seen a grey tank drain the same size as the black tank. The contents are not as large.

Are you in that much of a hurry?

[chabunga]

Our grey tank drains good at first, but then it slows to a trickle. And it will trickle for 10 minutes or more. I get tired of waiting and close the valve. What would cause that? My concern is some water will remain in the pipe and freeze and crack.

[JFlightRisk]

Originally Posted by chabunga

Our grey tank drains good at first, but then it slows to a trickle. And it will trickle for 10 minutes or more. I get tired of waiting and close the valve. What would cause that? My concern is some water will remain in the pipe and freeze and crack.

It may drain better, if you lower or raise the tongue so the tank outlet is lower than level. Ours trickles for a while, also.

[TaftCoach]

I check my level when parking to dump. If it isn't crowded I'll put a block under one side to help the drain especially if it's tilted away, which happens more than I ever thought it would..

[Grumpy]

Originally Posted by 01tundra

......looks like another mod on my neverending list.....

You will have to change the tank as part of that mod since the outlet on the tank itself is probably 1 1/2 too.

[Route 66 Traveler]

Originally Posted by chabunga

Our grey tank drains good at first, but then it slows to a trickle. And it will trickle for 10 minutes or more. I get tired of waiting and close the valve. What would cause that? My concern is some water will remain in the pipe and freeze and crack.

I have owned two RV's that had the same problem. Turns out it was from the small plastic disk that fell into the tank when they drilled it out for the drain pipe. Both times I was lucky enough to fish it out of the drain pipe and that restored full flow when draining.

You might try back flushing into the grey tank and see if that will improve draining, at least temporarily. That will give you a clue as to if there is a blockage or not.

[chabunga]

Originally Posted by Route 66 Traveler

I have owned two RV's that had the same problem. Turns out it was from the small plastic disk that fell into the tank when they drilled it out for the drain pipe. Both times I was lucky enough to fish it out of the drain pipe and that restored full flow when draining.

You might try back flushing into the grey tank and see if that will improve draining, at least temporarily. That will give you a clue as to if there is a blockage or not.

Thanks, I was thinking of trying to backflush the next time I was at the dump station. Also though of getting my grey water tank almost full before emptying it. How did you fish out the disk?

[Route 66 Traveler]

Both times I had emptied the grey tank completely. I looked up the pipe with a flash light and I could see where it was blocked. One was blocked in the 90 degree bend and the other time it was just wedged in the pipe about a foot behind the dump valve...that was the easy one. I took a coat hanger and put a hook at the end of the wire and was lucky to snag them both. Took a lot of patience and perseverance, but I got them both out.

[PoulsboJohnny]

Haven't put anything into either of my tanks yet since the rig is new and not used. Sure wish there were inspection ports on these things. My undercarriage is all covered up with the plastic board, which is a good thing, but it makes it really hard to look at the health of things.

[TCNashville]

You guys that are having problems with your grey tank draining and have determined that blockage isn't the issue, check for 2 valves inside your camper in the grey tank plumbing system. These are called air admittance valves and are usually located up under the bathroom/kitchen sink. Make sure these valves are functioning properly. If not the draining will be like holding your thumb on a straw filled with water and it'll drain ever so slowly.

[CAG]

Originally Posted by TCNashville

You guys that are having problems with your grey tank draining and have determined that blockage isn't the issue, check for 2 valves inside your camper in the grey tank plumbing system. These are called air admittance valves and are usually located up under the bathroom/kitchen sink. Make sure these valves are functioning properly. If not the draining will be like holding your thumb on a straw filled with water and it'll drain ever so slowly.

And malfunctioning valves will allow a bunch of stinky air back into the RV.

https://www.amazon.com/Studor-20341-...SIN=B00FQEX4UI

[pward]

Originally Posted by CAG

And malfunctioning valves will allow a bunch of stinky air back into the RV.

https://www.amazon.com/Studor-20341-...SIN=B00FQEX4UI

You have those under your kitchen and bathroom sinks?

[CAG]

Originally Posted by pward

You have those under your kitchen and bathroom sinks?

They are common in most all RVs. My toy hauler had them under kitchen and bathroom sinks. I replaced them with better quality.

[pward]

Okay. 1.5 to 2" seemed a little big is all, not the type of valve.

[Mekirk2]

Originally Posted by CAG

And malfunctioning valves will allow a bunch of stinky air back into the RV.

https://www.amazon.com/Studor-20341-...SIN=B00FQEX4UI

Old thread, new member - aren’t the roof vents designed to address this issue? Both the smell and the suction created when draining....