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Make #How to Fix Running Toilet Obsolete

Why is #How to Fix Running Toilet so popular?

Apparently it’s a big problem people need to fix.

So today we’re going to share how to fix a running toilet in 10 minutes by replacing the fill valve.

This is super easy and will save you a ton of money.

Let’s dive in!

Make #How to Fix Running Toilet Obsolete

Fill valves and flappers are the two big reasons toilets leak.

If there’s a slight drip in the toilet tank and the fill valve suddenly starts running it’s likely a flapper problem.

But fill valves that constantly run have to be replaced.

Fortunately fill valves are $10-$15 and only take a few minutes to swap out. For this project we used Fluidmaster’s 400H PerforMax valve.

The first step is to turn the water off at the shut off valve. If the shut off valve is broken turn the water off at the home’s main valve.

Then flush the toilet and hold the lever down until most of the water drains from the tank. Use a sponge to remove the rest of the water.

Unscrew the water supply line from the old fill valve, use Channellock pliers if necessary. Remove the old fill valve and dry fit the 400H.

The top of the Fluidmaster 400H should be roughly 3″ from the top of the flush valve. In addition, the top of the flush valve should be 1″ below the tank lever location.

Adjust the 400H height by turning the black column clockwise or counterclockwise. Then cut the hose to the right length so that it doesn’t catch on top of the toilet tank lid. Insert the hose into the clamp and attach it to the flush valve.

Secure the 400H to the bottom of the toilet tank using the provided nut, just hand tighten it. And hand tighten the water supply line to the bottom of the 400H. Turn on the water at the shut off valve and check for leaks.

Watch our video to make #how to fix running toilet obsolete

What’s Next

Home Depot and Fluidmaster have the 400H PerforMax available. It’s very affordable and will last for years.

Let us know if you have any questions, we’re happy to help.



Replace Toilet Fill Valve

  1. Bathobile Mdladla says:

    Wow, thank you it really clear.

  2. Frann says:

    Already knew this but so glad this simple fix is online for everyone to see. We don’t call a plumber unless absolutely necessary.

  3. Roger says:

    Shouldn’t you mark the waterline in the bowl after you pour in the 1 gallon of water?

  4. Joanne says:

    Is it written in stone that the tank needs to be emptyed

  5. Terry Templeman says:

    Replace toilet fill valve with the new 400H but every 4 to 5 minutes and can hear or see water running in the bowl did adjust bowl water height.

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