A double fixture fitting plays a crucial role in connecting two plumbing fixtures to a common drain line. Over time, these fittings can wear out, leading to leaks and potential water damage. Replacing a 1.5″ double fixture fitting is a manageable DIY plumbing project that can save you from costly repairs down the line. In this blog, we will provide a step-by-step guide to help you successfully replace a 1.5″ double fixture fitting and ensure a seamless plumbing repair.

  1. Gather the Necessary Tools and Materials: Before starting the replacement process, gather the necessary tools and materials, including a pipe wrench, plumber’s tape, a new 1.5″ double fixture fitting, and a bucket to catch any water that may spill during the repair.
  2. Turn Off the Water Supply: Shut off the water supply to the affected area by closing the water valves connected to the fixtures you’ll be working on. Make sure to drain any water remaining in the pipes to minimize spills.
  3. Remove the Old Fitting: Using a pipe wrench, carefully loosen and remove the old 1.5″ double fixture fitting from the drain line. Be cautious not to damage the surrounding pipes or threads during this process.
  4. Clean the Pipe Ends: Thoroughly clean the ends of the drain line where the old fitting was removed. Use a wire brush or sandpaper to ensure a smooth surface, promoting a secure connection with the new fitting.
  5. Apply Plumber’s Tape: Wrap plumber’s tape around the male threads of the new 1.5″ double fixture fitting. Plumber’s tape creates a watertight seal and prevents leaks in the future.
  6. Install the New Fitting: Carefully thread the new fitting onto the cleaned and taped pipe ends. Use a pipe wrench to tighten the fitting securely, but avoid over-tightening, as it may cause damage.
  7. Reconnect the Fixtures: Once the new fitting is in place, reattach the plumbing fixtures, such as sinks or toilets, to the fitting’s female threads. Tighten them appropriately to ensure a snug fit without leaks.
  8. Turn On the Water Supply: With everything securely connected, turn on the water supply to the affected area. Check for any leaks and make adjustments as needed.
  9. Test the Fixtures: Test the fixtures to ensure they are functioning properly and there are no leaks. Run water through the drains and inspect the connections for any signs of water seepage.
  10. Clean Up: Dispose of any debris, old fittings, and plumber’s tape properly. Clean up the work area and ensure everything is tidy and in its place.


Replacing a 1.5″ double fixture fitting may seem like a daunting task, but with the right tools, materials, and a step-by-step approach, it can be a manageable DIY plumbing repair. Taking the time to properly replace a worn-out fitting will prevent water damage and costly repairs in the future. If you feel uncertain about tackling this project on your own, don’t hesitate to consult a professional plumber. However, armed with this guide, you can confidently take on the task and enjoy a smoothly functioning plumbing system in your home.