6 Easy Steps to Replace a Toilet Flush Valve Seal

Replace the seal and flush your worries away

Brionna Farney
Written by Brionna Farney
Updated July 12, 2022
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Time to complete

5 minutes



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What you'll need:


  • Towel (optional)


  • New flush valve seal

Is your toilet constantly running? Or maybe pushing the handle has become a little more difficult recently? Both are signs that you might need to replace your toilet’s flush valve seal.

Fortunately, replacing a toilet flush valve seal is a simple task for anyone to take on by following the easy steps below. 

Prepping to Replace a Toilet Flush Valve Seal

You will need to purchase the right size flush valve seal for your particular toilet. Research the manufacturer and model of your toilet online to determine the size and type of seal that will fit before heading to the hardware store.

Also, your toilet will either use a tower-style flush valve with a seal or a flush valve with a flapper. If you find your toilet has a flapper, you will need to take alternative steps to replace your toilet flapper.

When your toilet stops working properly, it can quickly cause chaos throughout your entire household. Fortunately, in just a few minutes of your time, you can fix your toilet, and reestablish order.

  1. Drain the Toilet Tank

    First and foremost, you will need to drain the water from your toilet’s tank so you can access the flush valve inside. Turn off the water supply with the valve found at the base of your toilet, either near the floor or fixed to the wall. Flush the toilet so the remaining water drains from the tank.

  2. Disconnect the Refill Tube

    woman repairing toilet
    Photo: Klaus Vedfelt / DigitalVision / Getty Images

    Remove the lid from the top of the toilet tank. Locate the flush valve seal by looking for a red, blue, or yellow round seal beneath the flush valve tower. Feel free to dry off the flush valve assembly with a towel, if you prefer, before you start working on it. 

    Find the refill tube coming out of the top of the flush valve and disconnect it, either by pulling it out, unscrewing it, or removing a clip.

  3. Remove the Flush Valve Assembly

    First, unhook the trip lever that extends from the toilet flush handle to the flush valve along with any attached chain. Pull the flush valve tower assembly up and off of the center guide post and set it aside.

  4. Replace the Flush Valve Seal

    Remove the worn-out flush valve seal by pulling it out of the groove it rests in, up over the water line, and out of the tank to discard it. Grab your new seal and remove it from the packaging. Place the new seal in the groove where the old seal was seated.

  5. Reinstall the Flush Valve Assembly

    man closing toilet bowl lid
    Photo: hansgeel / Adobe Stock

    Reinstall the flush valve tower assembly over the water line and back into its original position. Reattach the trip lever, chain, and refill tube that were previously removed and place the lid back on the top of the toilet tank.

  6. Check the Install

    Turn the water back on to your toilet by opening the water supply valve, and allow the toilet tank to refill. Flush your toilet to check the install of your new flush valve seal. Listen for any leaks and make sure the toilet handle is easy to flush without any resistance. 

    If you do hear your toilet water continue running or if the handle is hard to flush, the seal may need to be re-adjusted to fit snugly and evenly around the groove. Ultimately, if replacing the seal did not fix the problem or if you run into any other toilet issues along the way, contact a professional plumber to assist you with a repair.

DIY Replacing a Toilet Flush Valve Seal vs. Hiring a Pro

Although replacing your toilet flush valve seal is fairly straightforward, not everyone is up for the task. If you are willing to get your hands dirty, you can expect to spend between $5 and $10 on materials for your flush valve seal replacement.

If you prefer to hire a professional for the job, expect to spend anywhere from $45 to $200 per hour. Consider hiring a local plumber to replace your valve seal and address any other lingering plumbing issues in your home during this service trip.

Additional Questions

How do you replace a fill valve seal?

Your toilet uses both a fill valve and a flush valve to operate, and both have a seal that may eventually require replacement. To replace a fill valve seal, start by shutting off the water to your toilet and draining the water from your toilet’s tank. 

Remove the fill valve cap from the top of the fill valve by rotating it clockwise a quarter-turn, using the fill valve arm as leverage. Locate the seal at the bottom of the fill valve cap and replace it.

Why is my toilet hissing after flushing?

The hissing sound coming from your toilet after flushing is a result of water or air being released into the toilet tank. There are a number of reasons for the noise, but it is likely related to your toilet’s fill valve. You will either need to clean the fill valve, replace the fill valve seal, or replace the entire fill valve assembly.

Are toilet flush valves all the same size?

Toilet flush valves are not all the same size. While 2 inches is the standard size for a toilet flush valve, that exact size might not be compatible with your particular toilet. Toilet flush valves range from 2 to 4 inches in size and vary from manufacturer to manufacturer. 

Research the exact type of toilet you have online to find the right size before purchasing a replacement toilet flush valve.

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