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Good Sam Roadside Assistance

Waste Water Not Draining Out of My RV's Shower

by karen

Tips On How to Unclog an RV Sink

Tips On How to Unclog an RV Sink

Why won't water drain out of the shower? First time out after winterized.

ANSWER: Hi Karen, the first thing I would suggest you do is to make sure that the grey water tank on your RV is not full. When greywater tanks get overfull, the greywater will start overflowing into the shower and the other sinks in your RV will start draining slowly or not at all.

I also suggest that you not trust the readings on the tank level gauges in your RV as they are notorious for being totally inaccurate. So your best bet is to dump the grey water tank and see if that resolves the drain problem in your shower.

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If the grey water tank was actually empty and/or the water still does not drain out of the shower after dumping the grey water tank, then that means you have a clog in the pipes leading from your shower to the grey water tank. Yes, the drain pipes in an RV can get clogged just like the ones in your stick home.

The first thing I would suggest you do is try to use a plunger on the drain to see if you can break the clog loose. If that does not work you may need to get some drain cleaner that is safe to use on PVC pipes. Depending on the severity of the clog, you may have to repeat the drain cleaning process.

Air Admittance Valve

SPECIAL NOTE: If this was the RV's Bathroom or Kitchen sink drain that was clogged instead of the shower. The first step that I would suggest is to go into the bottom sink cabinet and find the Air Admittance Valve (Pictured Above. An Air Admittance Valve acts like a sink roof vent in an RV. When you pull the plug on a sink full of water, the valve opens up and allows the sink to drain properly. If the Air Admittance Valve doesn't open up properly the water cannot drain properly and it should be replaced.

You can also try using a homemade Baking Soda and White Vinegar drain cleaner to unclog the drain. Simply dump as much baking soda as you can into the drain and then pour some White Vinegar into the drain until the baking soda starts to bubble. When the baking soda stops bubbling pour some more vinegar into the drain. Repeat this process 2 or 3 times or until the baking soda no longer bubbles. Now all you do is pour some boiling water down the drain and that should free things up.

Hope this helps.

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Happy RVing

RVing Al

Comments for Waste Water Not Draining Out of My RV's Shower

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Slow drain
by: Melody

We have a new RV! Noticed right of the tub was NOT draining well! My husband said when he turned on sink faucet, it drained faster!! Well, DIDNT FOR ME! What if we don’t have a vent thingy under the sink? I what then???

Tub not draining
by: Anonymous

We have a newer camper I looked under the sink I didnt see the airflow like the one pictured. Help please

Shower not draining
by: Stacy

My shower is not draining and I can’t find the valve under the sink. Help?!

Air admittance valve/slow shower drain
by: Johnny

I have a similar problem. With the grey tank empty, the first shower drains normally. But as I’m finishing my 2nd shower, I’m standing in a pool of non-draining water.

I go under the bath sink and unscrew the air admittance valve and I hear a swoosh of air and all the tub water drains.

Is my valve bad? What does it do? Why even have a valve there?


Air Admittance Valve

Note from RVing Al: In short, yes you should replace the Air Admittance Valve, it sounds like it is not opening properly to let the water drain out.

Shower wont drain
by: Rick

Air Admittance Valve

Had the same problem. It was a bad vent under the sink. Easy to replace. Six bucks at Lowes.

Note From RVing Al: The vent Rick is talking about is called an Air Admittance Valve (pictured above) and it could definitely be the cause of your problem.

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