Smart Countdown Control 32 Installation Guide

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→Smart Countdown Control 32 Installation Guide

Smart Countdown Control 32 Installation Guide

Congratulations on purchasing the most advanced microprocessor-controlled, hot water recirculation pump controller made. This system is designed to run the recirculation pump only when you need it thus saving both water and energy. It is designed and built with pride in the USA to provide years of service and savings.

Mandatory system test at the beginning of the QuickStart Guide must be performed in order to receive installation support.

Unboxing Your Product

1          Smart Countdown Control 32 with RJ-45 connector

Smart Countdown Control 32 Installation Instructions by Leridian Dynamics

1          ¾” or 1” NPT Flow Sensor with JST connector

3/4" NPT Hall Sensor Flow Meter

1          Wiring Harness with RJ-45 & JST connectors

Wiring Harness for Smart Thermostatic Control

Items Not Included: You will need the following items for installation that are not included.

→ PTFE (Teflon) Tape
→ Wire fasteners for securing wiring to the wall

You may need.

→ One or more 3/4″ NPT couplers to connect the flow meter depending on your installation.


Before you begin

Perform the following system test.

  1. Connect the wiring harness to the controller.
  2. Connect the flow meter to the wiring harness.
  3. Plug the controller into a wall outlet and ensure that the LED on the controller flashes green 3 times. (This will be followed by 60 seconds of the green LED blinking on and off every second while the controller is in provisioning mode.)
  4. Blow through the flow meter in the direction of the arrow and ensure the controller makes a slight audible click and the red LED turns on. It will stay on for approximately 5 minutes but you don’t need to wait for it to turn off. The test was to ensure that the flow meter can turn on the controller.

If this test fails, inspect the wires connecting to the flow meter to ensure they are not broken or loose. Reconnect the connection ensuring it snaps tightly and re-test.

Quickstart Install

  1. Install the flow meter at the cold water input to the water heater ensuring the arrow on the flow meter points in the direction of flow. NOTE: PTFE tape IS necessary when connecting to a female NPT connector. PTFE tape is NOT necessary when connecting to a flexible hook-up line as they have a washer that creates the seal. If installing in hard copper piping we recommend installing the flow meter using a union fitting.
  2. Connect the flow meter to the wiring harness and plug the wiring harness into the controller.
  3. Plug the controller into an outlet and plug the pump into the controller.
  4. Turn a hot water faucet fully on for 1 second and the pump will turn on and run for approximately 5 minutes.

If the pump fails to turn on see Troubleshooting Symptom 1.

LED Legend

GREEN LED: will blink 3 times when first plugged in to indicate the unit is functioning correctly.
GREEN LED: will blink once every second for 60 seconds after first being powered on to indicate the device is in provisioning mode.
GREEN LED: solid on when a timer is active and the pump is not running.
GREEN LED: will blink every 10 seconds when no other LED is lit (e.g. no timer active, pump not running)
RED LED: slow shallow breathing when the pump is running whether due to a timer or due to demand.
BLUE LED: solid on when connected via the smartphone app.
PURPLE LED: slow deep breathing when connected to the smart phone app via WiFi.


Please read over the following instructions. If you are not comfortable with any part of them please contact a licensed plumber to perform the installation.

Prior to installation you must perform the system test at the beginning of the Quickstart Guide.


  1. Note setting of water heater thermostat and then set to lowest temperature setting (do not turn off the pilot light).
  2. Shut off the cold water supply to the water heater.
  3. Open the closest hot water faucet to the water heater to depressurize the hot water line. When water quits flowing, turn off the faucet.
  4. Disconnect the cold water supply line from water heater.  Be careful not to bend and crease the supply line when manipulating it. Be prepared with some towels as some water will flow out of the hookup line. You don’t have to drain the tank. As long as all the faucets remain closed you should not get any back flow from the hot water line.
  5. Connect the flow meter to the cold water input of the water heater using PTFE tape being sure that the arrow on the flow meter is pointing toward the water heater.
    Smart Recirculation Control Flow Meter installation Leridian Dynamics
  6. Connect the cold water supply line to the input side of the flow meter. The supply line uses a washer to seal so you don’t need use PTFE tape on this connection. Hand tighten and turn an additional ¼ to ½ turn. DO NOT OVER TIGHTEN!
  7. Turn on the cold water supply to the water heater and inspect for any leaks.
  8. Turn water heater thermostat back to its original temperature setting.
  9. Connect the flow meter to the wiring harness via the JST connector ensuring it snaps together securely.
    Installation instructions for Smart Recirculation Control units from Leridian Dynamics, Inc. Connect the flow meter to the wiring harness via the JST connector
  10. Secure the wires to the wall away from the water heater.
  11. Plug the wiring harness into the Smart Countdown Control 32 via the RJ-45 connector ensuring it snaps in securely.

wiring harness Smart Recirculation Control 32 RJ-45 connector

  1. Plug the recirculation pump into the Smart Countdown Control 32 and plug the Smart Countdown Control 32 into an electrical outlet.
    Smart Recirculation Control 32
  2. The green LED on the side of the controller will blink 3 times if everything is okay.
  3. Turn a hot water faucet fully on for 1 This will trigger the recirculation pump to turn the pump on and run for the duration of the countdown time (default 5 minutes). The red LED turns on while the pump is running.
  4. Once the time is up, the pump will turn off and won’t turn on again until the dormant interval has expired (default 10 minutes).
  5. If the pump fails to turn on when a faucet is fully opened for 1 second, see Trouble Shooting item 1.

Smart Countdown Control 32 Setup with Smart Phone


If you need further support, please contact:

Leridian Dynamics, Inc. Customer Support or 831-761-8659