Hydrotek Flush Valve Troubleshooting

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Sensor-Operated Flush Valves:

Prior to 2017

After 2017

Parts of the Sensor-Operated Flush Valves:

To view all the parts of the Sensor-Operated Flush Valves, click here.

Please note: This includes both AC and Battery Powered versions prior to 2017 (pages 3 and 4) and after 2017 (pages 1 and 2).

Sensor-Operated Flush Valves Troubleshooting:

Battery-Powered and AC-Powered Flush Valves:

Normal Operation: When new batteries are inserted or AC power is connected or RESET button is pushed, the lights on the Printed Circuit Board (PCB) will blink in the following sequence: Red, Red (with solenoid clicking), Green, Red and Red. Green light will stay on. When the user enters the sensor beams' effective range, the red light will flash one time on battery-operated flush valves and will stay on with AC-powered models. If the user stays in the effective range for more than 4 seconds and steps away, the valve will activate (I) flush cycle. The flush valve unit will automatically reset for the next user. When the manual OVERRIDE button is pushed the flushing mechanism will be activated without impacting the mode of automatic operation. On battery operated models, the red indicator light flashes when batteries are low.

Please Note:

Always push the RESET button BEFORE diagnosing any problem and AFTER taking a corrective action
Worn batteries are the leading cause of malfunctions

Symptom- Flush Valve Will not Flush

Possible Cause	To Diagnose	Solution
Water does not turn on	Check water supply.	Turn water on at the valve
Power supply failure	Check polarity of batteries (or Power Adapter voltage), and connections.	Replace batteries (or Power Adapter), re-connect. Push RESET Button.
Batteries are weak	Red indicator light flashes, no click.	Replace batteries. Push the RESET button.
Sensor distance is too short	Stand in front of Flush Valve to find focal point of sensor beam.	To adjust sensor distance out, turn adjustment screw clockwise. Push the RESET button.
PC Board does not respond	No light, no action.	Replace batteries (or Power Adapter). Replace PCB. Push RESET button.
Sensor eye does not respond	Red indicator light does not blink.	Replace batteries (or Power Adapter). Replace sensor eye and cable. Push the RESET button.
Sensor eye angle adjustment	Beam not detecting user.	Disassemble control unit, rotate lens up/down with finger. Push the RESET button.
User time in sensor range too short	Stand in front of the Flush Valve. The red indicator light only flashes once.	Stand in sensor for more than 4 seconds, then move away. Push the RESET button.
Solenoid Valve is clogged.	Solenoid is clicking, but water does not flow.	Clean solenoid and blow free all by-pass holes. Replace solenoid. Push the RESET button .

Symptom - Flush Valve Will Not Shut Off

Possible Cause	To Diagnose	Solution
Solenoid coil malfunction	Light blinks but no solenoid clicking.	Replace batteries (or Power Adapter). Replace solenoid coil. Push the RESET button.
Solenoid is dirty	Solenoid valve is normally closed. Clicking sound means the solenoid is dirty.	Replace the solenoid valve. Push the RESET button.