RV Sink Drain Problems

RV Sink Drain Problems

Explore America's Campgrounds

Just like the sinks in your house, the sinks in an RV can have drain problems. Although it’s a bit inconvenient, the usual culprit is often food, grease or hair, and can often be fixed easily. Sometimes, the problem is a bit more unusual, like a clogged roof vent.

Plunge or Snake

A small bathroom plunger can be used on the sink to plunge it. If the sink is a double sink, put a rag into the second sink and plunge. The plunger has to have a flat bottom. Plunge the shower, as well. Some RVs are have plumbing set up so that the kitchen and shower run together.

Use a hair snake. Unlike the larger snakes that are made of metal, it is 3 feet or so in length, made of plastic and has jagged plastic running along the edges. Simply insert it into the drain and loosen objects in the drain, or pull hair out.

Living Microbes

Since RVs have a closed water system, consider using a product that contains living microbes to keep the drains clean. The living microbes love to eat drain scum, such as soap, hair, grease and other obstructions. Pour the microbial drain cleaner down the shower, bathroom sink and kitchen sink drain and let it sit for 24 hours. For this period, don’t use any hot water, as this will kill the living microbes.

Remove the P-Trap

This should be the last resort. It’s not that difficult, but it can get messy. A clog is usually in the p-trap. The p-trap is the pipe that makes a “U” shape under the sink. To remove this pipe, twist the connection counter-clockwise. It may require a plumber’s wrench. Make sure to have a bucket to catch the water and gunk in the pipe. Get a couple of towels to help with the cleanup.

Sink Water Runs Into Shower

On some RV units, when the grey tank is full, water from the kitchen sink will go into the shower. When this happens, empty the grey tank.

Roof Vent Clog

There is a vent attached to the plumbing that’s located on the roof. Over time, debris can get in it, or insects can build a home in it. Without this vent, the drain won’t drain. If it gets clogged up, it will slow draining or stop it completely. When the RV is hooked up to city water, you should notice a considerable difference as opposed to when you’re dry camping. Remove the roof vent, and run some water down the drain. This should clear the problem.


Make sure all the drains in the RV have a screen filter that catches food or hair. Don’t ever pour grease down the sink. Use the toilet’s large opening to get rid of anything that doesn’t appear to go down the sink easily (like last night’s soup). Fill your sinks with water once a month, and then let each one out slowly, one at a time.

Gone Outdoors