• In this video, This Old House plumbing and heating expert Richard Trethewey shows how to replace a rusted, ready-to-burst fitting.

    1. Turn off the gas or electricity to the water heater.
    2. Close the cold-water shut-off valve at top of water heater.
    3. Open all the hot-water faucets in house.
    4. Place a bucket under the valve near the bottom of the water heater. Drain some water from water heater into a bucket.
    5. Buff the cold-water supply pipe clean with emery cloth, then cut the pipe with a close-quarter tubing cutter.
    6. Use a pipe wrench to carefully remove the old, corroded fitting from the top of the water heater.
    7. Solder a short length of copper pipe onto a new threaded fitting.
    8. Wrap Teflon tape around the threads of the new fitting; be sure to wrap the entire threaded section.
    9. Tighten the new fitting into the top of the water heater with pliers.
    10. Slide a coupling onto the end of the cold-water supply pipe.
    11. Align the coupling with the new threaded fitting. Slide down the coupling to straddle the joint.
    12. Solder the coupling in place.
    13. Turn on the water to the water, then turn on the gas or electricity.
    • 1 to 2 hours, depending on the extent of the corrosion
    • $20 to $40, for typical repair
    • Difficulty: Moderate
      must possess basic plumbing skills, including how to solder

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      Video Directory

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      Tools List

      • close quarter tubing cutter
        Close-quarter tubing cutter
      • pipe wrench
        Pipe wrench
      • propane torch
        Propane torch
      • tongue-and-groove pliers

      Shopping List


      Copper pipe, threaded fitting and coupling

      Teflon tape

      Lead-free solder and flux

      Emery cloth