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Sloan G2 Retrofit Flushometer Complete Information

Posted on November 17 2020

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G2 Flushometer Installation Instructions, Info, and Resources


Sloan G2 Retrofits convert manual flush valves into touch-free, sensor-activated flush valves that perform well in high humidity, high activity, and low water quality situations. Not only are G2 retrofit kits a great way to make your flushometers touch-free for patrons, but they also have a very sleek appearance, and can be installed in less than 5 minutes. They quickly and easily fit into all existing Royal, Regal, and Sloan style flushometers, along with most other diaphragm valves.

Read this article to get full information on G2 retrofit units. Included in the article are installation directions directly from Sloan, along with tips from our team, comparisons to similar units, and additional resources like a photographic parts breakdown and troubleshooting flow chart. After reading this article, you will have all of the information needed to know if G2 units are the right choice for you. Be sure to save this page so you can reference it whenever you need to service your G2 units in the future.

Sloan G2 Optima Plus Retrofit Units versus Side Mount Operators

Once you decide to retrofit your manual flushometers and turn them into sensor-operated flush valves, how do you know which model to choose? That will depend on a few different factors. Essentially, there are two different types of retrofit kits: top mount, and side mount. G2 is a top-mounted style. SOLIS (solar-powered), SLOAN, and ECOS (dual flush) are other top mounted retrofit kit models. Side mounted models include Sloan EBV500A, EBV550A, EBV200A, EBV89A, EL600A, EL700A, and EL750A. Learn more about Side mounted units in our Side Mounted Retrofit Kit Comparison Guide. View all of the retrofit kits we have available on in our Retrofit Kit product section.

Two of the biggest differentiating factors between top mounted and side mounted units are the following:

  1. Top mounted units can be repaired, unlike side mounted options which are usually replaced when they stop working. So, a facility manager who is comfortable working on Sloan units might opt for a G2 unit because they can be repaired. However, a facility management team with less experience maintaining Sloan units may opt for side mount units, as they can simply replace units when they no longer function properly. 
  2. Top mounted units are considered to be more aesthetically pleasing, whereas side mounted operators are often considered to not be as attractive. For facilities that have a certain design style, this will often be a reason for choosing a G2 unit when making the change to sensor flushometers. 


What sets G2 units apart from all other sensor-operated flush valves is its patented isolated operator. The isolated operator allows for quiet, reliable, and consistent operation regardless of water quality. G2’s isolated operator can withstand aggressive water applications.



Sloan G2 flushometer retrofit


Sloan G2 Optima Plus Installation Instructions

These instructions are for retrofitting existing valves with G2 retrofit kits. For full instructions on how to install complete G2 units, read the full instructions starting with ‘Step 1’ in the Sloan Installation Instructions for Retrofit and Complete Valve Installation PDF. The instructions below start on step 6 because they are for retrofitting existing units with RESS model G2 retrofit fits. Start with step 1 in the PDF for installing complete G2 units. 


  1. Remove Components from Existing Flushometer
    *An extra H-553 Tail O-Ring is included. Use if leakage occurs if the valve is repositioned during the installation. Use only if needed.
    1. Remove the control stop cap.
    2. Turn off the water supply at the control stop. Push valve handle to relieve water pressure.
    3. Remove outside and inside part covers as well as old inside parts kit.
    4. Remove old handle assembly and gasket.
    5. Install chrome handle cap with gasket to the handle opening on the flush valve body. Tighten chrome handle cap until it is secure.


  1. G2 Optima Plus Flush Volume
  1. The flush volume of the G2 is controlled by the regulator in the flex tube diaphragm kit. The regulator’s flush volume is identified by color.


  1. Assemble Flex Tube Diaphragm to G2 Optima Plus Assembly

Wet the diaphragm to make installation easier.

  1. Ensure the flush volume regulator is installed past the o-ring.
  2. Insert the metal end of the diaphragm into the hole in the base of the G2 assembly. O-ring must be fully inserted into the hole. 
  3. Push diaphragm securely against the underside of the G2 Assembly. Place the entire assembly onto the valve body. Make sure the sensor lens is facing forward completely.


  1. Tighten the Locking Ring
  1. Thread the locking ring onto the valve assembly. 
  2. Use a strap wrench to tighten the locking ring. 


  1. Remove Tab to Activate Sensor Module
  1. Remove all removable objects in the sensor area to enable the sensor to properly sense its surroundings and adapt to the environment, then remove the tab that is located over the override button on the top of the unit. This activates the sensor module. The sensor module will then perform the start-up routine for one-minute, signified with LED blinking.
  2. For the first 10 minutes after the tab is removed, a red light will flash in the sensor window when a user is detected.


  1. Test Sensor Operation

The factory-set sensing range should be satisfactory for most installations. However, range adjustments can be made. Follow the instructions on page 6 of the Sloan G2 Complete and Retrofit Valve Installation Instructions PDF. The factory-set sensing ranges are as follows: Closet Models: 22 to 42 inches. Urinal Models: 15 to 30 inches

  1. Test the sensor with the cover in place
  2. Stand in front of the sensor for a total of 10 seconds.
  3. Step away from the sensor and listen for a ‘click’ sound.

Sloan G2 RESS Models

G2 Optima Plus Retrofit Kit Models

Sloan refers to their G2 retrofit kits as RESS Series Retrofit Conversion Kit models. As a reminder, retrofit kits are for installing on existing valves. For new installations, you must order G2 Complete Flushometers, not retrofit kits. Listed below are all of the retrofit kit options available:

Sloan G2 Retrofit Kits for Water Closets:

Sloan Model RESS-C-2.4 / Our Part Number: #81040 

Sloan G2 Retrofit Kits for Water Closets with Zurn Flushometers:

Sloan G2 Retrofit Kits for Urinals:

*Specify at check out for 1.5 GPF regulator

Sloan G2 Retrofit Kits for Urinals with Zurn Flushometers:

Additional Sloan G2 Optima Plus Flushometer Resources


G2 Parts Breakdown Image

G2 Flushometer Parts Breakdown and Troubleshooting Guide
Includes Photographic Breakdown, links to repair parts, Troubleshooting Q&A, and links to complete units. 



G2 Optima Plus Troubleshooting Flow Chart
Shares four G2 troubleshooting flow charts that each focus on a different common issue with the unit.


G2 Units and Repair Parts
View our selection of Complete G2 Flushometer Units, Retrofit G2 Units, or G2 Repair Parts to find and buy the complete G2 unit or G2 repair parts you need.


G2 Retrofit Kit and Complete Flushometer FAQs: 

Q: What is the difference between the G2 and the G2 Optima Plus?
A: Nothing. The Sloan G2 is the exact same item as the Sloan G2 Optima Plus. The naming convention has simply been shortened in recent years to just 'G2' instead of 'G2 Optima Plus'.


Did we answer all of your questions about G2 Conversion kits? If not, ask your question in the comments so we can provide you with an answer, and add your question to our FAQ section. Chances are if you have a question we didn’t answer in the article, so does someone else.


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