Toto Flush Valve Troubleshooting Guide (4 Issues Fixed!)

Your Toto toilet would never break if the world were perfect, but since it isn’t, you must learn how to fix your home fixtures. Toto flush troubleshooting will help you get to the bottom of the toilet problems and correct them.

The common Toto flush valve problems include failure to flush, continuous running, automatic turning on and off, and too little or too much water discharge. Explore these issues when you run into problems with your Toto toilet.

These issues stem from different causes, with some having multiple reasons. However, these problems are fixable, and this troubleshooting guide explores the causes and fixes in detail.

You will also find the steps for adjusting and cleaning the Toto flush valve. 

Why does my Toto toilet keep running?

Toto Flush Valve Troubleshooting (Problems & Fixes)

 ProblemPossible CauseQuick Fix
 1. Toto flush valve doesn’t flushThe control panel or water supply valve is turned off, No electric connection, The surface of the infrared sensor is stained or destroyed, The batteries are dead or installed correctly, The solenoid diaphragm’s small holes are clogged, The sensor has a reflective surfaceTurn on the valve, clean or replace the infrared sensor, reinstall or replace the batteries, clean the solenoid diaphragm’s small holes, and wire the valve
 2. Toto automatic flush valve keeps runningBroken zip, debris buildup, or faulty valve sealReplace the flush valve
 3. Toto flush valve turns on or off without flushingInsufficient slack in the flapper chain, a blinking red light on the sensor, or a dirty flush valve flapperClean the flush valve flapper, adjust the slack in the flapper chain, and replace the batteries.  
 4. Too little or too much dischargeThe handle/screw in the piston valve or control stop is improperly adjustedAdjust the handle or screw

1. Toto Flush Valve Does Not Flush

The most prevalent issue with Toto valves is that they do not flush. If this happens, check the following:

a) Electric Connection

The valve will not flash without a wire connected to electricity.


Check to see if the wire is connected and connect it if necessary.

b) Stain On the Surface of the Infrared Sensor

Stains on your infrared sensor will inhibit the flush valve operations.


Wipe the surface with a towel or clean it with a brush.

c) Clogging In the Solenoid Diaphragm

Your flush may not function if there’s any blockage inside the openings of the solenoid diaphragm.


Inspect the holes well and clean them with a wire or cloth.

d) Dead Batteries

Even if you fit the batteries according to the manufacturer’s instructions, the flush valve won’t work if they are dead.


Replace dead batteries

e) The Sensor Having a Reflective Surface at the Front

The flush valve will not function as effectively if the sensor has a reflecting surface.


Get a new sensor from a local distributor and replace the reflective one.

f) A Faulty Infrared Sensor Surface

Instead of collecting dirt, the infrared sensor’s surface might become ruined. If this happens, your valve won’t flush.


Call your distributor for a replacement or get a new one.

g) The Control Stop or the Water Supply Valve Turned Off

The flush valve relies heavily on the control stop and the supply to function effectively. Therefore, if you turn off either of them, or they shut off without your knowing, the flush valve won’t work.


  • Check to see if the control panel and the main valve have stopped. If they are off, turn them on.
  • Reinstall the flush valve.

2. Toto Automatic Flush Valve Keeps Running

The seal or the flapper is frequently to blame for the continual running water in Toto toilets; the rubber component in the automatic flush valve could be brittle or misaligned. In addition, debris buildup and a broken zip can make the valve run continuously.


  • Shut off the water supply and flush your toilet to drain the water.
  • Using a sponge or cloth, remove any residual water.
  • Detach the flush valve canister to access the seal.
  • Examine the seal for cracks and replace it if there are any.

3. Toto Flush Valve Turns on or off Without Flushing

When your flush valve turns on and off without flushing, the problem could be a dirty flush valve flapper, a blinking red light on the sensor, or insufficient slack in the flapper chain.


  • Clean the flush valve flapper.
  • Consider adjusting the slack in the flapper chain.
  • Replace the batteries.
How do you adjust a Toto fill valve?

Toto Flush Valve Replacement

Follow these steps to replace the Toto flush valve:

  • Shut off the water supply to your toilet at the angle stop.
  • Hold down the trip lever until you drain the tank water into the bowl. Remove the remaining water by hand.
  • Disconnect the water supply line from the fill valve and collect drips using a catch basin.
  • Undo the nuts on the left and right sides of the tank then remove the tank from the toilet.
  • Disconnect the tank to the bowl gasket from the tank’s underside and undo the large nut on the flush valve.
  • Unplug the flush valve from the toilet tank.
  • Install the replacement flush valve and secure the flush valve nut.
  • Attach the tank-to-bowl gasket.
  • Fasten the tank to the bowl until it touches the china.
  • Install the toilet water supply line by hand.
  • Turn on the water and test for leaks.

Toto Ecopower Flush Valve Troubleshooting

Check whether you shut off the primary water supply valve. If it is, then open it; otherwise, contact a professional.

Additionally, check for broken glass and contact your local distributor for a replacement.


  • Shut off the water to the flushometer.
  • Remove the cap and use a flat-blade screwdriver to turn the screw clockwise until the control stop closes.
  • Hold down the button to remove any remaining water.
  • Use the security hex wrench to loosen the top cover screws.
  • Lift the cover and disconnect the wires.
  • Unplug the battery, solenoid, and generator, then place the cover aside.
  • Unscrew and remove the valve cap then take out and discard the old piston.
  • Push the new piston into place. Next, replace and secure the valve cap.
  • Adjust the regulating screw to fine-tune the flush volume. It will change how long it will take for the flush valve to reset.
  • Turning the screw clockwise will reduce the flush volume; turning it counterclockwise will do the opposite.
  • Since the screw is sensitive, start with a half-turn and test the flushometer until you get the desired flush volume.

Toto Urinal Flush Valve Troubleshooting

Your Toto urinal could function below par because of a faulty or contaminated diaphragm. To correct this,

  • Shut off the primary water supply.
  • Disconnect the secondary line that supplies the urinal.
  • Lift the flush head cover and inspect the diaphragm to determine if anything is blocking it or broken and if it needs replacement.

Toto G Max Flush Valve Troubleshooting

What you flush down the Toto G-Max toilet drain stays flushed. Unfortunately, the features within the flush valves could get dirty, thus affecting the flushing system.

Some problems you could have with the Toto G Max flush are your toilet running between flushes and weak pressure when flushing.

Use the following methods to troubleshoot your Toto G Max flush valve:

How to Correct Water Running Between Flushes

  • Disconnect the primary water supply to the toilet and flush.
  • Lift the blue cover atop the fill-valve system and push the float arms inward to undo the float.
  • Use one hand to hold the flush valve and the other to spin the cap an eighth, then turn anticlockwise to remove it from the valve assembly.
  • Remove the middle tube and carefully remove the strainer from the tube using needle-nose pliers.
  • Reassemble the cap and strainer.

Fixing Weak Pressure When Flushing

  • Check that the water supply valve is completely open. If the toilet does not get enough water, it may not flush properly.
  • Examine the flush valve for damages. If you can’t see a fault in the valve, contact the manufacturer or a plumber to help you replace it.
  • If the flush buttons are stuck, lift the toilet tank lid and put it back on.
  • Use a plunger to remove clogging in the drain line.
  • Contact a plumber.

How Do You Adjust a Toto Flush Valve?

The flush valve is a cylindrical tube placed vertically inside the toilet tank. The procedure below will help you adjust the valve.

  • To unlock the tube, spin it anticlockwise about half a turn.
  • Set the flush tube to the appropriate water level.
  • Change the water level as desired by adjusting the flush tube. A marker on the tube should show the water level.
  • After moving the tube, secure it back in place by giving it a half-turn clockwise.
How do you adjust a toilet flush valve?

How To Clean Toto Flush Valve

  • Use a flathead screwdriver to detach the filter drain cover.
  • Turn the valve anticlockwise and pull it out.
  • Use a toothbrush to clean the flush valve.
  • Next, replace the flush valve.

Final Remarks on Toto Flush Valve Troubleshooting

It’s unfortunate when the Toto flush valve stops working. Therefore, understanding the model’s problems and solutions highlighted in this post will greatly help you solve flush valve issues when they crop up.

If the problem persists, consider calling a plumber to help you out.

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