water backing up into the shower/tub
 

We had our 95 TowLite out this weekend, and heard a gurgeling sound when washing dishes then water backing up into the shower. We dumped the grey tank, and still see a bit of water in the shower drain. I have checked the vent pipe to ensure the tank is being vented, but am concerned that the tank (grey) may not be emptied due to the visual water in the shower drain. Any ideas?

Thanks,

Gray water visible in shower drain.
 

Gray water may be visible in the shower as it is trapped the same as the sinks. A good reminder to allow your antifreeze to flow into these areas when winterizing.

what you are seeing is water in the trap which it and both sinks need some antfreeze dumped in them or they will freeze

Thank you for your suggestions to prevent freezing. Still, my question is why would when using the galley sink did my shower/tub back up with water.

Well, if your gray water tank is full the sink/vanity basin will back up into the shower pan. This happened to me!

There is a vacuum breaker vent under my kitchen counter,check this. You might have a build-up of junk in the drain pipe. My drainpipe that runs under the bathtub and behind the toilet does not have enough pitch to the pipe. Try snaking the pipe clean from the kitchen sink to the gray tank. You may have to remove the kitchen sink trap to do a good job.

Water always seeks its lowest level. Your shower/tub is lower than your kitchen and bathroom sink.

I too have a 95 T and a 2209T the fresh water tank is larger than the gray water tank, it is possible to run the gray water tank full, especially if you are hooked up to a water supply. The next lowest point in the system is the shower tube and the gray water will back up in there. When you look into the tub drain you are looking into the water trap and you will see water in it, even after draining this is normal. All RV trailers have a similar problem. You have to use as little water as possible when washing dishes, to prevent over flow, unless you are hooked up to a sewer drain.