RV Shower Drain Leak: How To Stay Dry And Stop Costly Damage

Water is the number one cause of permanent damage to an RV. Any leak, especially a drain leak, should be dealt with immediately.

The challenge with finding an RV shower drain leak is that the piping is difficult to access and determine where the leak is coming from.  The most common cause for an RV shower drain leak is loose sealant at the shower pan or loose fittings at the drain piping.  This post will review and guide you through the quick steps and fixes, including:

  • Investigating the Shower Pan
  • Checking the Shower Faucet
  • Inspecting Piping and Fittings
  • Tighten and Replace  Drain Lines

Following the guide below will help you investigate the common areas of water leaks and devise a plan to fix them while at the campsite. 

Table of Contents

RV Shower Leak

The first step in resolving a leak is to determine where that actual leak is coming from. It may or may not be obvious, as water can travel down a pipe and drip at another location.

To gain access to your shower piping, you must remove the access panel that leads to the shower piping. This is usually a piece of wall material that is screwed into place. Similarly, the panel or opening could be hidden in an adjacent cabinet.

To locate a leak, start where you see the water drip on the floor. This will be like a low point of a pipe or p trap. Now trace the water horizontally or vertically until you see no signs of water. Since water is easily moved by gravity, the highest point where the water stops is the area to focus on the leak.

Water leaks can travel down pipes.

Another easier identifier is checking for stain marks. Water will leave a mark, especially if it has leaked for some time. Look for the water stains and see where they start and stop. These will also be a clue in areas to investigate.

In an RV shower, here are some common locations for potential leaks.

Shower Pan

An RV shower pan or base is made of plastic and is sealed in place to the shower wall by caulking. Any break in the seal or movement in the shower surround can cause the caulking to separate the pan from the wall and cause water to leak under the shower floor. This is especially true with an RV shower tub or stall, as a person’s weight can easily push down or separate the pan from the wall.


Also, check the caulking around the faucet mounted to the wall. This is also an area where the caulking can separate. Since the faucet is penetrating into the shower stall, it has the potential to cause a leak.

If you notice that the leak could be from a bad seal, you will want to reseal the shower or tub surround. The best product to use is a Kitchen and Bath sealant that resists molding. Remove any loose caulking with a utility knife. Then recaulk that area. Allow for 24 hours before exposing that caulk to water.

Shower Faucet

Another location to check for leaks is the shower faucet and shower head. Any piping and fittings that supply the shower faucet can be suspected in the leak.

Inspect the piping and fitting and make sure they are all dry. Since these pipes are usually verticle, water drips down them fast, so it’s hard to tell visually. The best way is to feel with your hand for any signs of water.

If you notice a pipe or fitting leaking, you will need to replace it. Since most RVs use PEX piping, this is similar to some house plumbing. That means you can go to the local hardware store to get most of the parts and tools to replace. I suggest having the floor person walk you through your needs and how to go about your situation.

Drain Pipe

The next area to check is the drain pipe that leads from the shower to the grey water tank. This piping comprises a drain pipe, p trap, and a strainer. The piping size is 1 1/2″ PVC piping. Similar to what is at the home center, except usually a thinner and lighter material for RVs.

RV drain parts

This drain assembly is not meant to hold any pressure. It must drain the water as quickly as possible to avoid leaks. Knowing this, you will want to check for any debris that may be causing a clogged drain. Clear it out if you notice a clog, and see if that has stopped your leak. If not, continue to investigate the drain pipe.

Drain Pipe Repair

Inspect the drain piping and p trap fittings. These compression fittings use pressure to hold the two pieces of plastic together. Hand-tighten any loose fittings to increase the pressure and connection of the pipe pieces.

Also, many of the plastic piping on the market fuse two-half pieces of piping together. Sometimes, this weld can come loose, and you will get a crack and leak in the piping. If you notice this, replacing the piping is the best thing to do.

Final Thoughts

Water damage is the primary cause of RV damage, making it crucial to address any leaks promptly, particularly drain leaks. Identifying the source of an RV shower drain leak can be challenging due to limited access and location uncertainties. Common causes include loose sealant at the shower pan or drain pipe fittings. Investigating the shower pan, checking the faucet, inspecting piping and fittings, and examining drain lines are essential steps to locate and fix the leak.