DIY Network

How to Install a Recirculating System

Learn how to install a re-circulating system to keep a continuous flow of water moving through a hot water heater out to the fixtures.

More in Plumbing

  • Time

    1 hour

  • Price Range

    $250 - $500

  • Difficulty



Step 1: Prep the Water Heater

Turn off the power to the water heater, or turn the unit to 'pilot' if it's a gas heater. Shut off the water from the water heater.

Note: If a point-of-use system is already installed, it needs to be unplugged.

Turn on the faucet to drain the water lines. Leave it on until after the system is installed.

Next, let the water heater cool down. Once it's cooled, disconnect the hot water feed line from the water heater using slip-joint pliers.

prep water heater

Step 2: Secure the Discharge Connection

Hand-tighten the recirculating pump onto the discharge connection.

Note: Make sure the flow arrow on the pump is pointing away from the water heater.

Tighten everything down with a wrench.

Attach the hot water line to the discharge connection on the pump.

secure discharge connection

Step 3: Install the Re-circulating Valve

Install the recirculating valve (Image 1) at a sink the greatest distance from the water heater.

Shut off the water under the sink.

Remove the supply lines to the sink (Image 2). Replace with stainless flex-lines.

Attach the flex-lines to the recirculating valve and then attach the valve to the water stop (Image 3).

Turn on the water and check for leaks. Turn on the faucet to purge air from the water line.

Step 4: Complete the Installation

Plug the point-of-use system back in. Next, turn on the water heater.

Plug in the pump that was installed on the water heater.

Safety Tip: Be sure to keep the electrical cord away from the water heater flues if it's a gas or oil heater.

Set the timer on the pump.

set timer on pump