How to Change a Toilet Flush Valve?

1. Prepare Tools and Materials

Before starting, make sure you have the following items ready:

1) New Toilet Flush Valve (Flush Valve or Dual Flush Valve)

When purchasing a new flush valve, ensure the size and model match your toilet. The most common sizes are 2-inch and 3-inch, which can be determined by the diameter of the old valve’s outlet.

Also, check whether your toilet is two-piece or one-piece. For two-piece toilets, choose a flush valve that uses a locknut to secure it. For one-piece toilets, select a model that uses a steel bracket for tightening.

2) Adjustable Wrench

For two-piece toilets, the locknut at the bottom of the tank may be hard to remove by hand, so a wrench will help you loosen it.

3) Screwdriver

For one-piece toilets, use a screwdriver to loosen the central screw inside the tank that holds the flush valve.

2. Step-by-Step Replacement Guide

1) Shut Off the Water Supply and Drain the Tank

Turn the angle valve clockwise to stop water flow. Press the flush button (for dual flush valves, press the full flush button) to completely drain the tank.

2) Remove the Old Flush Valve

For two-piece toilets, use a wrench to loosen the locknuts connecting the tank and the bowl, then carefully remove the tank. Next, detach the old flush valve assembly from the tank bottom.

For one-piece toilets, simply unscrew the central fixing screw inside the tank to remove the valve.

3) Install the New Flush Valve

Insert the new valve into the mounting hole at the tank bottom. Adjust its position so the rubber gasket fits tightly. Tighten the locknut or bracket securely—but avoid over-tightening.

4) Reinstall the Tank and Reconnect the Water Supply Line

For two-piece toilets, position the tank back in place and align the bolt holes. Tighten the bolts evenly. Reconnect the water supply hose, ensuring a proper seal at each joint.

5) Test for Leaks and Flush Performance

Turn on the angle valve to refill the tank. Check the bottom for any leaks and test the flush button. If the flushing system runs smoothly with no leaks, your installation is successful.

3. Tips to Extend the Flush Valve’s Lifespan

1) Choose high-quality materials such as ABS, POM, or PVC for better durability and anti-aging performance.

2) Clean the inside of the toilet tank regularly to prevent scale and debris from affecting the seal.

3) Replace toilet tank fittings every 3–5 years to maintain optimal flushing and prevent hidden leaks.

4. Conclusion

Replacing a toilet flush valve is a simple but essential maintenance task. By following the correct steps, you can make your toilet work like new again.

If you are unsure which flush valve model to choose, check the toilet brand manual or look up related installation videos online.

As a professional manufacturer of toilet tank fittings, Xiamen Jielin Plumbing Co., Ltd. provides a wide range of flush valves, fill valves, push buttons, and accessories.

Our products cover both single flush and dual flush systems, compatible with various brands and models to meet diverse market needs.