How to install a circulating pump on a hot water tank

Updated February 21, 2017

If you have to let the water run a long time before it's warm enough to take a shower, you're probably a victim of conventional design. Hot water tanks are large, unattractive objects usually relegated to basements or garages. As a result, your hot water heater may be quite a distance from your bathroom. By installing a circulating pump on the water tank, you can keep the hot water flowing when you want it most.

Turn off the water supply to the hot water tank. Look for a valve on the cold water line running into the tank. If there isn't one, you will have to turn off the water at the meter outside your house. Open a hot water tap inside your house to relieve pressure on the hot water line. Leave this tap open until you have completed your installation.

Place a rag on top of the tank around the hot water outlet. Disconnect the hot water outlet line from the tank with an adjustable spanner. Wrap plumber's tape around the hot water outlet nipple.

Locate the arrow on the circulating pump to determine the direction of flow. Install the pump with the arrow pointing away from the hot water tank. Thread the pump connecting nut onto the nipple and tighten.

Attach the house hot water line to the pump outlet. Don't use plumber's tape on the outlet if installing a flexible line with a gasket. Hold the pump steady and tighten the connection with an adjustable spanner.

Turn the water supply back on. Allow air to bleed from the hot water line until water runs normally, then turn off the hot water tap you left open earlier. Check for leaks and tighten connections if necessary. Plug in the pump electrical cord and set the timer according to the manufacturer's instructions.


Make the job of installing a recirculating pump much easier by installing a flexible connector on your hot water tank outlet line at the same time.


Make sure you position the pump and its electrical cord away from the flue of a gas or oil fired water heater.

Things You'll Need

  • Adjustable spanner
  • Rags
  • Plumber's tape
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About the Author

Steve Hamilton has been writing professionally since 1983. His credits include novels under the Dell imprint and for Harlequin Worldwide. A remodeling and repair specialist with over 20 years experience, he is also a Certified Pool Operator and holds an EPA Universal refrigerant certification.