How to Fix a Small Hole in a Water Heater

Updated April 17, 2017

Leaks in hot water heaters must be fixed. Beyond the obvious loss of heat and water, energy bills can soar with a large, inefficient appliance. Fortunately, relatively simple techniques help temporarily repair a small hole in a hot water heater. However, most pin holes are developed from corrosion and rust, and cannot be stopped entirely forever. Despite this reality, certain accepted types of repairs from savvy homeowners have become part of the DIY repair playbook.

Dip the toothpick into the jar of plumber's putty. Insert the toothpick into the hole until it can go no farther. Leave the toothpick for 15 to 20 minutes, allowing water to make the toothpick expand, filling the hole.

Shear off the portion of the toothpick still extending from the water heater, using the flathead screwdriver. The water inside the tank should have caused the toothpick to expand, filling the hole. The plumber's putty will seal any smaller openings for water to escape.

Wipe off excess plumber's putty around the repaired area, using the clean rag. Monitor the leak for a few days to ensure that the repair has taken hold.


Put on rubber gloves before doing anything with hot water. This will protect you from potential hot drips, although it is rather unlikely you'll encounter much water.

Things You'll Need

  • Toothpicks
  • Plumber's putty
  • Small flathead screwdriver
  • Clean towel
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About the Author

David Lipscomb is a professional writer and public relations practitioner. Lipscomb brings more than a decade of experience in the consumer electronics and advertising industries. Lipscomb holds a degree in public relations from Webster University.