Gray water tank won't empty

Hi all,

When we dumped our tanks last weekend, we got little if anything from the gray water tank. I postulated that it was because our TM was very lopsided at the dump station so we decided to leave things be and head on home. The co-owner of the trailer attempted to dump the gray water tank yesterday (trailer is on level ground) and while she got some drainage, it still wasn't the volume she expected. The system panel light indicates the gray water tank is still 1/3 full.

I have suggested that she try putting the curb side wheel on blacks to tilt the trailer towards the dump valve and/or taking the trailer for a spin in the hopes that water sloshing around will loosen/break-up any clog.

Anyone have any other ideas on what could be keeping the tank from draining completely and how we might fix it?

Thanks!

You didn't indicate in your post if you were hooked up to to sewer while you were camping. If you were, there is the possibility that the graywater dump valve was leaking by into the sewer. This seems possible since your indicator is still showing the tank only 1/3 full.

If I was having this problem, I would run water into the gray water tank until it started coming up into the bathtub. If this takes a while to do, it would demonstrate that the tank is indeed only 1/3 full. If that is the case, I would then make sure the graywater dump valve was closed, take off the cap, place a bucket under the outlet, and then come back later and see if there is any liquid in it. If there is, the valve is leaking by and is defective or needs cleaning.

If there is more liquid in the tank than the 1/3 indicated and you are not able to dump it, your graywater dump valve is most likely broken. The handle has broken loose and is not sliding the valve open.

Hope this helps and doesn't cause you to do a lot of work for nothing.

Michael (One of the TandemKids)

[fcatwo]

It's also possible the tank is empty and residue on the sides of the tank is affecting the gauges. Nothing about the TM or any other RV is less reliable than the tank gauges (the TM toilet being an exception). I'm not sure we've even looked at our gauges in the 3 yrs we've owned the TM.

To add to that, I was told by our dealer, "If even a hair is sitting on the gauge it can cause it to read wrong." There are Thetford products to use for cleaning drains, and lubricating the valves. He said to use one of those.

[wbmiller3]

Sometimes when I am dumping the waste fluids, nothing comes out when I open the gray water valve. I just bounce the bumper up and down a couple of times and then it comes gushing out just fine. Perhaps there is some kind of vaccuum being pulled on the tank?

[Bill]

A while back, I sneaked a peek at another RV website (yes, I admit I do it from time to time). One poster recommended adding powdered water softener (see http://www.calgon.us/) to the toilet or gray tank to dissolve "stuff". He said it did a great job of cleaning out the tanks. See his discussion at

http://www.newrver.com/holdingtank.html

So you could throw in some water softener, drive for a few miles to slosh things around, and then dump. I've been meaning to try it. Anyone have any experience?

On the other hand, if the problem is the slider valve as described by TandemKids, you should be able to discover this easily. Remove the cap from the dump connector, and look up into the mouth of the pipe. You MAY be able to see the gray water slide valve, I'm not sure. If not, straighten out a wire coathanger and push it up into the gray water dump pipe (the smaller of the two, obviously). With the slide valve closed, the wire shouldn't penetrate very far. With the slide valve open, it should move right on up.

Bill

[Joesjunk]

My grey water sensors don't work.
After I dump the tank, the lights still indicate 1/3 full. Did some tests. Filled the tank till the lights indicated full.
Continued to put water in the tank for a very long time until I saw water in the tub. I let it set over night and dumped the clean water out. Still indicates 1/3 full.
Next time I'm at an RV store I'll check on new sensors or some cleaner for the sensors. I camp at many campgrounds that do not have sewer connections, so, I like to know how much tank I have left.

Thanks for all the ideas! I've shared them with Janet (the TM's co-owner) so she has some things to try when she takes it out this weekend.

To add to the info from my original post, we were semi-dry camping with the only hook-up being electric (and that in itself was a rare treat indeed ). We did get some drainage from the gray water tank, but nothing like what would be expected from having used up almost all of the fresh water. Given that, I'm inclined to think that the sensor is actually reporting correctly. Anyway, if there are any updates from this coming weekend, I'll be sure to share .