Maintaining an RV is essential to keeping it in top shape and preventing costly repairs. One common issue RV owners may encounter is a failed backflow preventer in the city water connection. This can allow water to flow back through the hose, leading to standing water in the wet bay and potential water damage.

In this guide, I’ll explain how to diagnose and replace a faulty city water connection in your RV based on my recent repair experience with my rig, Bertie Bea.

Here’s the video that shows the entire repair and what it took.

Understanding the Problem: Backflow Preventer Failure

The city water connection in an RV is designed to allow pressurized water from an external source to flow into the plumbing system while preventing backflow. A built-in backflow preventer ensures water does not reverse direction and contaminate the water supply.

If you notice standing water in your wet bay or water leaking from the city water hose, the backflow preventer may have failed. This means it’s time to replace the city water connection.

Tools & Materials Needed

Before starting the repair, gather the following tools and materials:

✅ Electric Screwdriver – To remove the existing fitting.

✅ Replacement City Water Connection – Ensure you get a model that fits your RV. I used an all-plastic version from B&B, the manufacturer of the original fitting.

✅ Butyl Tape – Helps create a watertight seal.

✅ Gloves – To keep your hands clean and dry.

✅ Towels – To clean up any residual water.

Step-by-Step Instructions for Replacing the City Water Connection

1️⃣ Remove the Existing Water Connection

• Locate the city water connection in your wet bay.

• Unscrew and disconnect the water line from the back of the fitting.

• Use an electric screwdriver to remove all screws securing the old connection.

2️⃣ Prepare the New Connection

• Check whether the replacement fitting is a single-piece or two-piece unit.

• Roll a strip of butyl tape into a thin “spaghetti” shape and place it along the outer edge of the new fitting. This will ensure a tight seal against leaks.

3️⃣ Install the New City Water Connection

• Position the new fitting in the same spot where the old one was removed.

• Secure it in place using the screws you removed earlier.

4️⃣ Reconnect the Water Line

• Attach the water hose to the back of the new city water fitting.

• Make sure all connections are tightened properly to prevent leaks.

5️⃣ Test for Leaks

• Turn on the city water supply and check for any leaks.

• If necessary, tighten the connections further or add more sealant to ensure a proper fit.

Why Learning Basic RV Repairs Matters

One of the reasons I feel confident in tackling these repairs myself is thanks to the Family RV Association’s (FRVA) “RV Basics” training program. This course, offered at most FRVA International Conventions, provides hands-on learning about RV systems and maintenance. Instructors like Gary, Steve, and Eric break down the fundamentals, empowering RV owners to handle common issues themselves.

In my five years of RV ownership, I’ve learned that every repair is a learning opportunity. If you own a motorhome, understanding basic maintenance can save you time, money, and headaches down the road.

Final Thoughts

If your RV’s city water connection starts failing, replacing it is a straightforward repair that you can handle with a few tools and some patience. Learning to perform basic RV maintenance will not only keep your rig in great condition but also enhance your confidence as an RV owner.

Happy RVing, and enjoy the journey! 🚐💨