American Standard Flush Valve Troubleshooting Guide

Although American Standard products are made of quality materials and made to last, they develop issues just like other things. American Standard flush valve troubleshooting guide is essential for homeowners with these toilets.

The common flush valve-related issues in your American Standard toilet include continuous running and water shortages. Other problems are too much water flow, continuous flushing, flushometer problems, and flushometer sensor issues.

This troubleshooting guide is well-formulated to help you address different American Standard flush valve issues. It also provides the steps for adjusting the flushometer sensor and how to know you need to replace your flush valve.

American Standard automatic Flush Valve manual

American Standard Flush Valve Troubleshooting (Quick Fixes)

The table below summarizes problems you can diagnose with your American Standard flush valve and how to fix them. Have a look.

 ProblemPossible CauseRecommended Fix
1.Toilet running continuouslyOld/faulty flush valve sealsReplace the flush valve seals
2.Shortage of waterProblems with the water supply line
Incompatible sensor
Check the water supply
Install the correct sensor
3.Excessive water flowIssues with the water supply
Installing incorrect sensor
Examine the water supply line
Install a sensor that is compatible with your unit
4.Flushometer won’t flushDirty or worn-out piston assemblyReplace the piston assembly
5.Continuous flushingDeteriorated rubber seal
Faulty solenoid
Replace the rubber seal
Replace the solenoid

American Standard Toilet Running Continuously

Do you hear sounds of water flowing continuously into the toilet bowl without human intervention? It signifies you have leaking problems in your toilet that could arise from old and faulty flush valve seals.

Toilets should always stay clean and dry. However, one with an old and broken flush valve seal will disappoint you, especially when you have visitors in your apartment.

Fixing American Standard flush valve seal problems is easy, and you only need needle-nose pliers, a towel, and a blue accelerator flush valve seal.


  • Press the trip lever, separate the clevis pin from the trip lever rod, and slacken the top cap.
  • Remove the float assembly while maintaining a low water level to detect an old and faulty valve seal and other components.
  • Use pliers or your fingertips to pull out the faulty flush valve seal until it breaks.
  • Roll the seal around the trip lever holder to stick it.
  • Use needle-nose pliers to pull the seal backward to maintain the trip lever in the center hole of the replacement seal.
  • Depress the trip lever to remove the clevis pin.
  • Disconnect the flush valve chain by lifting the flapper.
  • Release the flapper, remove the flapper seal, and replace it with a new one.
  • Replace the flush valve chain on the flapper and tighten it to avoid water flow problems caused by the unstable flush valve chain.
  • Replace the flapper in your toilet tank.
  • Reconnect the clevis pin and the trip lever rod, leaving sufficient room for the new seal to return to the trip lever holder.
  • Place the flush valve seal between the knob of the trip holder and where the tank attaches to the trip lever.
  • Keep pulling the elastic water refill tubing from the middle of the stop cap.
  • To contain water leaks from the refill tube after flushing, position the free end downwards. If there is any leakage, replace the water refill tube and the seal on the stop cap.
  • Flex and carefully draw the new seal downward past the vertical assembly towards the overflow tube.
  • Allow the seal to float to the bottom while remaining in the top groove attached to the flush valve.
  • Flush your toilet and check whether the new flush seal is effective. Additionally, check the position and condition of the flush valve.

Important Points

Before replacing the faulty or outdated flush valve seal, cut off the water supply to your toilet tank and flush the toilet or press the handle downward to drain water from the tank.

Also, when troubleshooting a running American Standard toilet, avoid using colored chemicals to treat the water in the tank. Colored water limits your ability to see American Standard automatic flush valve parts that need replacement.

If the toilet is still running after this process, the flapper valve could be the problem.

How To Adjust American Standard Flush Valve

Having looked at American Standard flush valve (View on Amazon) replacement, it is vital to know how to adjust the flush valve. Follow the simple procedure below to tweak the American Standard flush valve.

  • Twist the adjustment screw atop the valve clockwise to raise the water level and anticlockwise to reduce the water level.
How do you fix an American Standard toilet that keeps running?

American Standard Selectronic Flush Valve Troubleshooting

When the sensor is triggered, the solenoid activates and releases water from the upper chamber, which reduces the pressure. The high water pressure from the inlet, which lifts the piston and moves it down the flush pipe, follows this.

When you flush, some water is forced back into the upper chamber through the small bypass in the piston. It continues until the pressure equalizes and pushes the piston toward the valve seat.

American Standard Selectronic flush valve is not flawless. You’ll encounter problems like:

a) Shortage of Water

The main culprit of water shortage, in this case, is the water supply. The water flow rate depends on the pressure, the size and length of the pipe, as well as the number of fixtures in a building that affects the flow rate of each flush.

In addition, using an incompatible sensor can also result in a shortage of water.


  • Check the water supply.
  • Open the control stop until you get a normal flush.
  • Install the correct sensor, one that is compatible with your unit.

b) Excessive Water Flow

Sometimes, your fixture may have excess water flowing after each flush. It stems from problems with the water supply or installing an incompatible sensor.


  • Check the water supply and regulate the water getting into your fixture.
  • Install a sensor that’s compatible with your unit.

c) Flushometer Won’t Flush

Flushing problems arise from having dirty piston assembly. If the unit doesn’t flush manually, examine the control stop to see if the water is on, then clean the piston assembly.

If the flushometer doesn’t flush automatically, press the manual override button. If the fixture flushes manually but fails to do so automatically, disconnect the battery pack and replace it.

If the battery pack doesn’t give a red flash, consider getting a new one. On the other hand, flashes of red light without activating the solenoid mean you have to replace the latter.

However, you might have replaced the solenoid in an American Standard automatic flush valve urinal, to no avail. If that happens, experts advise you to get another sensor module.


  • Press the manual override button if the system doesn’t flush automatically.
  • Check the control stop for any flaws.
  • Clean or replace the piston assembly.
  • Replace the solenoid.
  • Replace the sensor module

d) Continuous Flushing

Rubber seals on the piston deteriorate, causing water from the upper chamber to leak. It prevents the upper chamber from pressurizing.

If the piston maintains this raised position, it can induce continuous flushing. Apart from issues with the rubber seal, a defective solenoid causes non-stop flushing. If it remains open, water will keep flowing out and impede the upper chamber from pressurizing.


  • Replace worn-out rubber seals.
  • Close the solenoid (or replace it if it is faulty).

American Standard Flushometer Sensor Adjustment

Before delving into American Standard flushometer sensor adjustment, it’s worth mentioning that the default sensing range for water closets and urinals is 16 inches. However, you can adjust it to 32 inches if you wish.

Follow the procedure below to adjust the flushometer sensor.

  • Loosen the set screw on the back of the cover using a 2.5 mm hex wrench.
  • Lift the cover and unplug the battery pack.
  • Wait 10 seconds, then reconnect the batteries and replace the cover. As you do this, keep your hands away from the sensor.
  • After 5 seconds, begin the sensor setup.
  • Reconnect the power supply, and check for a red light flash.
  • Place your hands at least two inches away from the sensor.
  • Once you see the red light, move your hand to your chosen distance and hold it in place until the red light flashes again.
  • Remove the hand from the front of the sensor.
  • When the light stops blinking, it implies you have successfully programmed a new detection distance.
  • Tighten the set screw to secure the cover.
How to fix American Standard flush valve?

How Do You Know If A Flush Valve Needs Replacing?

When you hear your toilet running continuously, hear the noise emanating from the valve, or see a leak from the supply line coupling, you need to replace the flush valve as soon as possible. A faulty flush valve produces a persistent hissing sound, signifying malfunction.

Final Remarks On American Standard Flush Valve Troubleshooting

American Standard toilets running continuously, non-stop flushing, shortage of water, excessive water flow, and the flushometer not flushing are the most common problems plaguing American Standard flush valves. Thankfully, this piece has diagnosed these problems and given expert fixes.

If you are unsure about troubleshooting flush valve issues, contact experts to help you.

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