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Smart Thermostatic Control 32
for Tankless Water Heaters Troubleshooting Guide

Table of Contents

TROUBLESHOOTING

LED Legend

GREEN LED: will blink 3 times when first plugged in to indicate the unit is functioning correctly.
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: solid on when the pump is running whether due to a timer or due to demand.
BLUE LED: solid on when connected via the smartphone app.

1. SYMPTOM: The pump won’t turn on when hot water is drawn from a faucet.

ISSUE 1: If the controller has run within the dormant interval, the pump won’t automatically turn on when flow is detected.

RESOLUTION: Unplug the controller from power for 10 seconds and plug it back in. This will reset the controller and it will now turn on automatically when it detects flow. Turn a hot water faucet fully on for 1 second and then turn it off. If it still doesn’t turn on see ISSUE 2.

ISSUE 2: The high sensitivity value is set to high for the controller to detect the flow provided by the faucet.

RESOLUTION: Open the smartphone app to the “Live Flow”TM view. This will show what flow value the controller is sensing. Turn the hot water faucet fully on and watch the flow value. If it goes greater than 20 then the pump will turn on. If it doesn’t go greater than 20 then you will need to reduce the sensitivity value to be less than the maximum value you observed.
NOTE: If you are seeing very low flow at the faucet it is possible the aerator in the faucet is clogged. Removing it and tapping it to remove any accumulated sediment can restore the flow, but they are inexpensive so replacing it is recommended.

2. SYMPTOM: The pump won’t continue running after the initial pump run time expires.

ISSUE 1: The thermostatic crossover valve(s) is (are) already heated up and aren’t allowing flow.

RESOLUTION: Check the temperature of the water at the location of the crossover valve(s) and see if the water is 95°F. If it is, wait for the water to cool off and test it again. If it is not 95°F, see ISSUE 2.

ISSUE 2: The low sensitivity value is set too high and the controller isn’t registering enough flow to keep the pump running.

RESOLUTION: Open the smartphone app and go to Settings → Advanced Settings and set the Initial Pump Run Time to 30 seconds. Go back to “Live Flow”TM and touch the “Trigger Pump” button. The pump will now run for 30 seconds and you should see the flow value that the pump is pushing through the thermostatic crossover valve(s). If this value is 0 then the crossover valve(s) is (are) closed and not allowing flow. If this value is not 0, then set the low value in Settings → Sensitivity to be less than this value and the pump will continue to run when triggered.

Remember to go back to Settings → Advanced Settings and set the Initial Pump Run Time back to 5 seconds.

3. SYMPTOM: The pump continues to run after hot water is detected at the faucet(s) where the thermostatic crossover valve(s) is (are) installed.

ISSUE 1: The thermostatic crossover valve(s) is (are) not up to 95°F and therefore still allowing flow.

RESOLUTION: Check the temperature of the water at the location of the crossover valve(s) and see if the water is 95°F. If it is 95°F, see ISSUE 2.

ISSUE 2: The low sensitivity value is set below the flow value the controller is registering and therefore keeping the pump running.

RESOLUTION: Open the smartphone app and go to the menu and select “Live Flow”TM. The flow value that the controller is registering will be displayed. Go into Settings → Sensitivity and set the low value to be greater than this value and the pump will turn off.

4. SYMPTOM: The pump turns on when no hot water is being drawn.

ISSUE: Pressure spikes in the cold water supply line caused by abrupt turning on or off of the cold water (for instance when a toilet fills or a sprinkler system turns on or by fluctuations in the feed from the utility company) can cause the Smart Recirculation Control 32 to trigger the hot water recirculation pump to turn on.

RESOLUTION: The sensitivity value of the Smart Thermostatic Control 32 is too low and should be adjusted higher. The default value of 20 works well, but can be susceptible to these false triggers. It is recommended to increase it by 5 pulses at a time to filter out these anomalies.

5. SYMPTOM: No flow is seen on the “Live Flow” screen when a faucet is opened.

ISSUE 1: A wire connecting the flow meter is broken.

RESOLUTION: Inspect the wiring harness where it connects to the flow meter to ensure none of the three wires appear broken. If they are contact Leridian Dynamics to get a replacement harness. If it looks good see ISSUE 2.

ISSUE 2: Sediment or scale is blocking the flow meter.

RESOLUTION: To ensure that this is indeed the issue perform the following test. Remove the sensor from the flow meter that is held on with 2 small silver screws (don’t worry, it won’t leak water when the sensor is removed). Start the smartphone app, view the “Live Flow” screen, and quickly wave a magnet back and forth over the sensor. You should see the flow value change. The flow meter works by spinning a magnet on a turbine that is read by the sensor. If you see a flow value in the smartphone app then the flow meter is blocked with sediment or scale and will need to be removed and cleaned. If you do not see a flow value then there is an issue with the sensor and/or the wiring harness and it will have to be replaced.