8/12/24

Uninvited Guests: Your Step-by-Step Guide to Getting Rid of Bugs in Your RV Shower Drain

Hey there, fellow road warriors. Let's talk about something a little less glamorous than epic sunsets & scenic drives: the creepy crawlies that can sometimes show up in our RV shower drains. You know what I'm talking about – those little black flies or gnats that seem to appear out of nowhere, turning your cozy bathroom into a bit of a bug-out zone. It's a SUPER common problem, so if you're dealing with it, don't worry, you're not alone.
Honestly, it can be pretty frustrating. You keep your rig clean, you're careful about what goes down the drains, & yet, these little pests decide to make your plumbing their new home. Here's the thing, though: getting rid of them is totally doable. It just takes a little know-how & a bit of persistence. I've been there, done that, & I'm here to walk you through everything you need to know to reclaim your shower & keep those bugs out for good.

So, What ARE These Bugs & Where Are They Coming From?

First things first, let's identify our uninvited guests. Most of the time, the culprits are drain flies (also known as sewer flies, sink flies, or moth flies). They're small, fuzzy, dark-colored insects that kind of look like tiny moths. They're not the strongest fliers, so you'll usually see them hanging out on the walls of your shower or near the drain itself.
The reason they love our RVs so much is pretty simple: our plumbing systems are a perfect breeding ground. They thrive in moist, dark environments with plenty of organic gunk to feed on. Think soap scum, hair, shed skin cells, & all the other lovely stuff that accumulates in our P-traps & holding tanks. That's a five-star hotel for a drain fly.
Their lifecycle is also pretty speedy. A female drain fly can lay up to 300 eggs at a time, & those eggs can hatch & develop into adults in as little as a week or two. This is why it can feel like you have a full-blown infestation overnight. One minute you see a couple of flies, the next they've invited all their friends & family to the party in your bathroom.
The primary breeding grounds in your RV are:
  • The P-trap: This is the U-shaped section of pipe under your shower drain. It's designed to hold a small amount of water to block sewer gases from coming up into your rig. But, it also collects all sorts of debris, creating a perfect sludge for drain flies to lay their eggs in.
  • The Gray Water Tank: All the water from your shower & sinks goes into the gray tank. Over time, a layer of slime & gunk can build up on the inside walls of the tank, providing an ideal habitat for these pests.
  • The Black Water Tank: While less common for shower drain issues, if you have a combined system or a cross-contamination problem, the black tank can also be a source.
  • Sewer Hookups: Sometimes, if you leave your gray tank valve open at a campground, flies can travel up the sewer hose from the campground's septic system & into your RV.

Step 1: Confirm the Source with a Simple Test

Before you go all-in on cleaning, it's a good idea to confirm that the bugs are actually coming from your shower drain. Here's a super easy way to do that:
  1. Dry the drain: Wipe the inside of the drain & the area around it as dry as you can.
  2. The Tape Test: Take a piece of clear packing tape, sticky side down, & place it over the drain opening. Don't completely seal it, as you want to allow for some airflow.
  3. Wait: Leave the tape in place overnight, or for at least a few hours.
If you come back & find little flies stuck to the tape, you've found your culprit. This confirms they're coming up from the drain & not from somewhere else in your RV.

Step 2: The Initial Assault - Getting Rid of the Adult Flies

Now that you know where they're coming from, it's time to deal with the adult flies that are currently buzzing around your bathroom. This will give you some immediate relief while you work on eliminating the breeding ground.
One of the most effective & popular DIY methods is the apple cider vinegar trap:
  1. Get a small bowl or cup.
  2. Pour in about an inch of apple cider vinegar. The flies are attracted to the fermented scent.
  3. Add a few drops of dish soap. This breaks the surface tension of the vinegar, so when the flies land to take a sip, they'll sink & drown.
  4. Place the trap near the shower drain. You can also cover the bowl with plastic wrap & poke a few holes in it. This makes it easier for the flies to get in but harder for them to get out.
You'll be surprised (and a little grossed out) by how many flies you catch with this simple trick. There are also commercial fly traps & electric bug zappers you can use, but honestly, the vinegar trap works wonders & you probably already have the ingredients on hand.

Step 3: The Main Event - Eliminating the Breeding Ground

Okay, this is the most important part. Killing the adult flies is a temporary fix. To get rid of the problem for good, you need to destroy their breeding ground. This means thoroughly cleaning your P-trap & your gray water tank. Here are a few different methods you can use, from gentle, natural solutions to more heavy-duty options.
Method 1: The Boiling Water Flush (The First Line of Defense)
This is the easiest & most immediate thing you can do. Boiling water can help to dissolve some of the soap scum & gunk in your pipes, & it will kill any eggs or larvae it comes in contact with.
  1. Boil a large pot of water.
  2. Carefully & slowly pour the boiling water down the shower drain. Be careful not to splash yourself!
  3. Repeat this process a few times over the next couple of days.
While this is a good first step, it's often not enough to completely eliminate a stubborn infestation on its own. The water cools as it goes down the drain, so it might not be hot enough to kill everything in the P-trap or further down the line.
Method 2: The Baking Soda & Vinegar Volcano (A Classic for a Reason)
This is a classic cleaning combo that's safe for your RV's plumbing & surprisingly effective. The chemical reaction between the baking soda & vinegar creates a fizzing action that helps to scrub the inside of your pipes & break down the gunk.
  1. Pour about a half cup of baking soda down the drain.
  2. Follow it with a half cup of white vinegar.
  3. Immediately plug the drain. You want to keep that fizzing action contained in the pipes.
  4. Let it sit for at least 30 minutes, or even a few hours.
  5. Flush the drain with another pot of boiling water.
This is a great, non-toxic way to clean your drains & it's something you can do regularly as a preventative measure.
Method 3: Enzyme-Based Drain Cleaners (The Safest & Most Effective Option)
If the natural methods aren't cutting it, your next best bet is an enzyme-based drain cleaner. These are a lifesaver for RV owners. Unlike harsh chemical drain cleaners (which we'll talk about in a minute), enzyme cleaners use beneficial bacteria & enzymes to break down & "eat" the organic waste that the flies feed on.
They are specifically designed to be safe for RV plumbing & septic systems. They won't harm your plastic pipes or the rubber seals on your valves. Brands like Zep, Green Gobbler, & Drainbo are popular choices in the RV community.
Here's how to use them:
  1. Follow the instructions on the product label. Each product is a little different, so it's important to read the directions carefully.
  2. Typically, you'll pour a certain amount of the cleaner down the drain at night, when you won't be using the water for a while. This gives the enzymes time to work their magic.
  3. You may need to repeat the treatment for a few nights in a row to completely eliminate the infestation.
Enzyme cleaners are fantastic because they not only get rid of the current problem, but they also help to prevent future ones by keeping your pipes & tanks clean.

A Quick Word on What NOT to Use: Harsh Chemical Drain Cleaners

It might be tempting to reach for a bottle of Drano or Liquid-Plumr, but PLEASE resist the urge. These products are NOT safe for RV plumbing.
Here's why:
  • They can damage your pipes & seals: RV plumbing is made of lightweight plastic & has rubber seals in the valves. The caustic chemicals in these cleaners can eat away at these materials, leading to leaks & expensive repairs.
  • They can harm your holding tanks: These chemicals can kill the beneficial bacteria in your holding tanks that are essential for breaking down waste.
  • They're bad for the environment: When you dump your tanks, these harsh chemicals can end up in the septic systems of campgrounds or in the local water supply.
Stick to the safer, RV-friendly options. Your plumbing system will thank you.

Step 4: Don't Forget the Gray Tank!

Since the gray tank is a major breeding ground, you'll want to give it a good cleaning as well.
  1. Dump your gray tank completely.
  2. Add your chosen cleaner. You can use an enzyme-based tank cleaner or even the baking soda & vinegar method. For a large tank, you might use a couple of cups of baking soda & a half-gallon of vinegar.
  3. Add a few gallons of fresh water.
  4. If possible, go for a drive. The sloshing action will help to clean the sides of the tank.
  5. Let it sit for a few hours or overnight.
  6. Dump the tank again & rinse it thoroughly.

Long-Term Prevention: Keeping the Bugs Away for Good

Once you've won the battle, you need a long-term strategy to prevent the bugs from coming back. Here are some simple habits to get into:
  • Regularly clean your drains: Once a week or so, pour some boiling water down your drains, or do a quick baking soda & vinegar treatment. This will prevent gunk from building up.
  • Use an enzyme cleaner monthly: Make it a part of your regular RV maintenance routine to treat your drains & holding tanks with an enzyme cleaner. This is probably the single most effective thing you can do.
  • Keep your gray tank valve closed: When you're hooked up at a campground, resist the temptation to leave your gray tank valve open. This creates a direct highway for bugs from the sewer system into your RV. Keep it closed & dump the tank when it's full.
  • Create a P-trap in your sewer hose: If you absolutely must leave your valve open, create a "P-trap" in your sewer hose by letting it dip down in the middle & then come back up. This will create a water barrier that can help to block pests.
  • Use drain strainers: A simple mesh strainer over your shower drain will catch hair & other debris before it goes down the drain & becomes bug food.
  • Keep your RV clean: Wipe down your shower & sinks regularly to prevent soap scum buildup.

What If I'm Storing My RV? A Quick Note on Bug Prevention

If you're getting ready to store your RV for a while, it's the perfect time to think about pest prevention. The last thing you want is to come back to a rig full of bugs. Before you park it, do a thorough cleaning of your plumbing system using the methods we've talked about.
And speaking of storage, sometimes the bigger issue is not having a good place to keep your RV when you're not on the road. Leaving it in an open field or on the street can expose it to all sorts of pests & weather. If you're looking for a safe & secure spot, you might want to check out a service like Prked. It's a pretty cool platform that connects people who have extra space – like a large driveway, a side yard, or even a garage – with RV owners who need a place to park. It can be a much more affordable & convenient option than traditional storage facilities. Plus, keeping your RV in a well-maintained residential spot can help reduce the chances of pests making it their home.
It's also a great way to earn some extra income if you're a homeowner with some spare space. You could be helping out a fellow RVer while making a little cash on the side. Just a thought!

Tying It All Together

Dealing with bugs in your RV shower drain is a pain, there's no doubt about it. But as you can see, it's a problem with a clear solution. By understanding where these pests come from, getting rid of the existing infestation, & then putting some simple preventative measures in place, you can keep your RV's plumbing system clean & bug-free.
It really comes down to being proactive. A little bit of regular maintenance goes a LONG way in the world of RVing. So, the next time you see one of those little flies, don't panic. Just follow these steps, and you'll be back to enjoying your bug-free home on wheels in no time.
Hope this was helpful! Let me know if you have any other tips or tricks that have worked for you. Happy trails
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