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Sloan ESS Exposed Sensor Flushometer Troubleshooting

Posted on April 20 2021

Sloan ESS Exposed Sensor Flushometer Troubleshooting


This article contains information to help you understand the differences between various Sloan ESS Exposed Sensor Flushometer units. It also includes troubleshooting tips directly from Sloan’s senior field and technical support technicians. Like all flushometers, Sloan’s ESS Exposed Sensor Flushometers have components that will need to be replaced over time. Understanding and maintaining hardwired sensor operated Sloan flushometers is easy when you have resources to help you troubleshoot when you run into maintenance tasks. Use this article to help you keep your Sloan ESS flushometers in top condition. 


ESS Exposed Sensor Flushometers

ESS Exposed Sensor Flushometers are sensor-activated hardwired flushometers for closet and urinal applications. They are also referred to as Optima units, which means that they are hardwired flushometers (as opposed to Optima Plus, which implies the unit is battery operated). They come in a variety of models including Royal, Regal, Sloan, and Crown. ESS flush valves utilize an electronic solenoid sensor that uses infrared (IR) technology, and feature true-mechanical override functionality. They share many components with existing manual flushometers, including 24 VAC power supplies, making them a great option when upgrading from manual to sensor flushometers.


Sloan Acronyms for ESS Flushometers

These are the acronyms used throughout Sloan’s product information and installation guides for ESS flush valves:

  • ESS – Electronic Solenoid Sensor
  • TMO – True Mechanical Override
  • OR – Override Button
  • HW – Hard-wired
  • WB – Wall Box
  • SWB – Small Wall Box
  • SBX – Wall Plate with Integrated TMO aka “LaGuardia style”


Installing Sloan ESS Flushometers

Sloan ESS Flushometers can be used for the following applications: water closets, urinals, utility service sinks, bedpan washers, and squat toilets. Most commonly, they are used in water closet (EL-1500-L) and urinal (EL-500) applications, both of which use the EL-1500 Sensor Assembly. 


ESS Sensor Plates


The sensor plate is available in Regal / Sloan and Royal styles. All ESS Wall Plates are designed to be screwed into electrical boxes. Here is Sloan’s Rough-In Template for Royal, Regal/Sloan, & Crown 110 ES-S /111 ES-S sensor plates.

All ESS Exposed Sensor Flushometers use dual sensor and solenoid plates for closet installations, and a single combination sensor and solenoid plate for urinal applications. Royal, Sloan and Regal are all diaphragm type flushometers, and Crown is a piston type. The Royal model uses the Royal sensor plate style, and all other models (Regal, Sloan, and Crown) use the Regal / Sloan sensor plate style. The True Mechanical Override button is optional on all models. The TMO retrofit kit for all models is the EL-1026A. They all utilize a 24 VAC power supply. 



Troubleshooting Tips for EL-1500 Urinal Sensor 


Indication of Error: Continuous slow flashing red LED
Issue: Improper start-up notification.
Resolution: Disconnect the power for 30 seconds, then repeat the installation procedure.


Indication of Error: Continuous fast flashing red LED
Issue: Sensor is detecting a target.
Resolution: Remove the obstruction, or clean the sensor window.


Indication of Error: Red LED flashes an “SOS” pattern (3 short, 3 long)
Issue: Wiring connections are not correct, or there is an electrical shortage.
Resolution: Rewire the sensor correctly, and repeat installation procedure. Note that this will most likely occur after initial set up, indicating that the wiring was not connected properly.


Indication of Error: LED lights are not working
Issue: No power to the unit
Resolution: Check the power supply to make sure it is functioning, and repeat installation procedure. If it flushes, then the sensor is not working. The replacement sensor for urinals is EL-1500. For closets, it is EL-1500-L. If it does not flush, then there is no power to the unit.



Troubleshooting Sloan ESS Exposed Sensor Flush Valve Units

Sloan senior field and technical support technicians state that the most common culprit of issues for the ESS units are the sensor assembly and override button. Second is the solenoid. Third, the actuator cartridge, and then eventually, the diaphragm. 


Sloan replacement parts ESS Flushometers


Below is a list of troubleshooting tips for ESS Flushometers that Do Not Flush. Possible scenarios listed are from most common scenario to least likely scenario. 


Symptom: Sensor LED is blinking, but unit does not flush. The override button works.
Cause: The sensor is not calibrated.
Solution: Power off the unit for 60 seconds, then power it on again so the sensor can auto adjust for 60 seconds. Do not block the sensor during this time. 


Symptom: Sensor LED isn’t blinking or activating a flush. The override button works.
Cause: Either (1) the sensor is damaged, or (2) the sensor was wired incorrectly.
Solution: Either (1) replace the EL-1500 Sensor (for urinals) or EL-1500-L Sensor (for closets) or (2) rewire it properly.


Symptom: Sensor LED blinks, but doesn’t activate a flush. Solenoid makes buzzing noise. Override button works (or buzzes with no flush).
Cause: Either (1) High static pressure about 80 PSI or (2) Undersized wiring, insufficient voltage.
Solution: (1) Reduce the static pressure, or (2) reinstall with 18 gauge wiring (minimum), replace the transformer with an EL-154 transformer.


Symptom: Sensor and override button are working, but the solenoid buzzes (may trick water to bowl) and does not activate a flush. 
Cause: Either (1) the solenoid is corroded, oxidized, or stuck, or (2) the solenoid shaft assembly is damaged.
Solution: (1) Replace the EL-124-2 solenoid, or rebuild with EL-163-A solenoid shaft assembly repair kit. (2) Replace with EL-163-A solenoid shaft repair kit.


Symptom: The Sensor and override button work, but the solenoid clicks and does not flush.
Cause: The actuator cartridge is clogged with debris, is damaged, or improperly reassembled.  
Solution: Clean and reassemble the EL-128-A actuator cartridge assembly, or simply replace it.


Buying Sloan ESS Flushometers


Equiparts sells all models of Sloan ESS True Mechanical Override (TMO) Flushometers, as well as the repair parts needed to maintain them. Most items are in stock and ready to ship. Not all units are listed on our website, so you will need to call to place your order for models other than the Royal ESS True Mechanical Override (TMO) Flushometers. You can view Royal models in our Optima ESS True Mechanical Override (TMO) Flushometers product section. 


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