How to Eliminate a Water Hammer After Flushing a Toilet

Water hammer can cause serious damage to plumbing fixtures.

New quick-closing toilet fill valves can cause water hammer situations in many plumbing systems. Ways to eliminate water hammer after flushing a toilet include installing a permanent water hammer arrestor at the toilet supply, installing a whole house bladder tank at the water heater or individual fixture arrestors in several locations throughout the home. Installing a small, pressure-absorbing bladder tank on the cold water supply of the home's water heater is the best solution. Installing the tank will require some plumbing skill. The experienced do-it-yourselfer should have no problem with the pipe connects required.

Things You'll Need

• Tubing cutter
• Emery cloth
• Flux
• Acid brush
• Copper fittings
• Bladder tank
• Thread tape

Instructions

1. Turn the main water supply off to the water heater, either at its individual fixture cut-off or at the main house supply.

2. Cut the copper supply pipe with tubing cutters in a horizontal location. Sand the pipe ends and fittings with emery cloth. Coat the outside of the pipe and inside of the fittings with flux; use a small acid brush. Install a tee fitting facing up. Cut a 2-inch piece of copper pipe and insert it into the top of the tee, and then slip on a female adaptor. Solder all the joints with a torch and lead-free solder. Wipe the joints clean with a rag and allow them to cool.

3. Wrap thread tape around the male threads of the pressure tank several time to insure a watertight connection.

4. Screw the tank onto the fitting by hand.

5. Turn the water back on and check for leaks.

Tips & Warnings

• Always install the tank between the fixture cut-off and water heater.

• Installing the tank vertically is always the best choice.

• The bladder tank should be preset to an adequate pressure; however, adjustments my need to be made.

• Not following the manufacturer's instruction could cause personal injury and property damage.

References

• Natural Handy Man: Water Hammer
• Watts: Thermal Expansion
• Irrigation Tutorial: Water Hammer and Air in Pipes

Resources

• Water Hammer: Practical Solutions B. B. Sharp, D. B. Sharp