Fixing a Running Toilet: DIY Tips

A running toilet is a common issue in many homes where water keeps flowing into the bowl after flushing. Fixing this problem can save you money and stop wasting water. Since November 25, 2019, our guide has shown over 6.3 million viewers how to repair their toilets for less than $20.

It’s easy enough even if you’ve never tried plumbing before.

Inside a toilet tank are parts like the flapper and fill valve that sometimes break or wear out. Our article makes it simple to figure out which part might be causing trouble. You’ll only need some basic tools like pliers and maybe a new fill valve from the store.

James Schuelke, a plumber with thirty years of experience, shares his knowledge here too. He helps by breaking down tasks such as turning off the water and checking different parts inside your toilet tank so they make sense.

We also touch on more advanced fixes, such as adjusting tube heights and chains but don’t worry; we explain everything step by step with diagrams to help you see what needs doing.

For times when DIY won’t cut it, we tell you when it’s best to call in a pro plumber instead—you don’t have to go at it alone!

Let’s fix that leak!

Understanding How a Toilet Functions

A toilet has several key parts that work together. First, there is the tank behind the bowl. It holds water until you flush. When you push the flush handle, it lifts a rubber piece called a flapper valve at the tank’s bottom.

This action lets water rush from the tank into the toilet bowl through an opening.

As water empties from the tank, two things happen at once: The flapper drops back down to stop more water from escaping and a float falls as well due to lower water levels. This fall triggers the fill valve to open.

Fresh water flows in through a supply line at the bottom of your tank. Water pours into both the tank and bowl via tubes and pipes – one being an overflow pipe which makes sure your tank doesn’t overfill by draining excess back into the bowl if needed.

Once filled to a set level, which is controlled by an adjustment screw on some models or by bending a float arm in others, everything stops until your next flush!

Identifying the Cause of a Running Toilet

To find out why your toilet keeps running, check the flapper first. A worn-out flapper often causes leaks because it doesn’t seal properly. Look for signs of decay or damage on the rubber.

If the flapper seems fine, move on to inspecting the fill valve for defects. Sometimes mineral deposits can cause malfunctions here.

Next, measure the overflow tube’s height to make sure it’s not too tall causing water to constantly drain down it. Also, listen for a hissing noise that could signal an issue with your water supply line or fill valve.

Fix these problems and you’ll be one step closer to lower water bills and better water conservation. Ready? Grab your tools and let’s fix that leak in section four!

Required Tools and Materials for Toilet Repair

Gather your adjustable wrench, screwdriver, and replacement parts because having the right tools and materials is crucial for a successful toilet repair.


To fix a running toilet, you’ll need some tools. Make sure you have everything before you start.

  • Adjustable wrench: Use this to loosen and tighten nuts and bolts on the toilet.
  • Screwdriver: A flat-head or Phillips screwdriver will help with screws on the toilet handle or tank.
  • Plunger: If the toilet is clogged, a plunger can clear the blockage.
  • Gloves: Wear rubber gloves to protect your hands from germs and dirt.
  • Bucket: Keep a bucket nearby for any excess water that needs draining.
  • Sponge: A sponge will soak up water from the bottom of the tank.
  • Towels or Rags: Use these to clean up spills and wipe down surfaces.


Fixing your running toilet doesn’t have to break the bank. You can get all the materials you need for less than $20.

  • A new fill valve: This part controls the water that refills your toilet tank after each flush.
  • Adjustable wrench: Use this tool to loosen and tighten nuts on the fill valve.
  • Replacement flapper: A faulty flapper often causes leaks. Make sure you get one that fits your toilet model.
  • Flapper chain: This connects the flapper to the flush handle, so it needs replacing if worn out or too long.
  • Rubber gloves: Keep your hands clean while working inside the toilet tank.
  • Teflon tape: Wrap this around threads of the fill valve to prevent leaks at connections.
  • Sponge and bucket: To mop up any leftover water in the tank before starting repairs.
  • Replacement washers and bolts if necessary: These secure your toilet tank to its base and may need replacing if they’re corroded.

Steps to Fix a Running Toilet

Follow these practical steps to remedy your running toilet, ensuring water efficiency and potentially reducing your utility bills – keep reading for a straightforward DIY fix.

Turn Off the Water Supply

Find the water valve near your toilet. Twist it clockwise to shut off the water flow. This step stops more water from filling up the tank and is essential before any repair work. Make sure you turn the valve until it won’t move anymore to be certain the supply is completely cut off.

Once you’ve turned off the water, flush your toilet. This drains out most of the water in the tank, making it easier for you to inspect and fix parts inside without a mess. Now that your tank is empty, go ahead and lift off its lid carefully—your DIY toilet repair adventure gets serious here!

Remove the Tank Lid

Once you have turned off the water supply, carefully lift off the toilet tank lid. Hold it firmly on both sides to keep a good grip. Place the lid away from your work area to prevent it from getting damaged.

Look inside the tank to see all the parts: flapper, fill valve, and float. Handling these parts is easier with the lid off. James Schuelke advises being gentle as breaking any components can cause more problems.

Now you are ready to inspect each part and find out what’s causing your toilet to run.

Inspect the Flapper

With the tank lid off, take a close look at the flapper. This rubber seal stops water from flowing from the tank to the bowl when not flushing. Check if it’s warped or damaged. If it is, this could be why your toilet keeps running.

Gently lift the flapper and inspect its edges for any signs of wear or decay.

Find out if there’s a tight seal between the flapper and the bottom of the tank. Any gaps mean that water can leak through, causing continuous running. Flappers often become brittle with age, so replacing an old one might solve your problem right away! If adjustments are needed, make sure they’re done correctly to prevent future leaks and save on your water bill.

Examine the Fill Valve

Look at the fill valve to see if it’s working right. If the tank is not filling up properly or water keeps running, the fill valve might be faulty. Find this part on the left side of the tank.

It’s attached to a tall plastic tube known as the ballcock. First, check that nothing blocks its path and no parts look broken.

Make sure you test the valve after turning your water back on. Watch how it responds when you flush. The goal is for no water to flow through when the tank is full and for there to be a steady refill stream when it’s low.

Next, let’s deal with replacing the fill valve if needed.

Replace the Fill Valve if Necessary

Check if your toilet’s fill valve is faulty. Look for signs like a hiss or water running when the toilet isn’t in use. A bad fill valve can cause constant refilling, leading to higher water bills.

Shut off the main water supply before you start. Flush the toilet to drain most of the water from the tank. Unscrew the old fill valve under the tank and lift it out carefully. Grab your new fill valve and make sure it’s set to the correct height according to manufacturer instructions.

Place it in position where you removed the old one, then screw it tight.

Connect everything back up – attach all nuts, washers, and hoses securely. Turn on your water supply again and check that everything works with no leaks.

Professional plumber James Schuelke advises being precise during installation; this ensures a leak-free fit and saves future trouble!

Advanced Repair Steps

6. Advanced Repair Steps: Delve deeper into toilet repair with advanced techniques and adjustments that ensure your system operates smoothly, promising further savings on water bills and heightened efficiency in your bathroom’s essential fixture—read on to master these pivotal skills.

Check the Overflow Tube Height

Measure the overflow tube to ensure it’s at the correct height. The top of this tube should be lower than the cistern’s critical level mark, usually a line inside the tank. If it’s too high, water can flow into it without ever filling the tank enough to lift the float and stop the inlet valve.

To fix this issue, adjust or replace the overflow pipe with one that meets your toilet’s specifications for size and height.

For tubes that are adjustable, simply twist them to change their sizes or push down gently until they reach an appropriate level. Non-adjustable ones may need cutting or replacing entirely with a new piece.

Always double-check that adjustments made do not cause leaks around fittings or disrupt other components within your toilet system.

Adjust the Water Level in the Tank

After checking the height of the overflow tube, turn your attention to the water level in the tank. It should sit 1 to 1.5 inches below the top of this tube. Find the fill valve; it controls water flow into the tank.

Look for a screw on its top—this is what you’ll adjust.

Turn this screw counterclockwise to lower how sensitive the valve is. This will stop too much water from filling up your toilet tank and spilling over into the tube. Keep an eye on the water level as you make these adjustments, ensuring it does not go above or fall short of that ideal mark just below the overflow tube’s edge.

Making sure your flush system has just enough water saves on your bill and helps prevent leaks!

Inspect the Flush Valve Chain

Check the flush valve chain in your toilet tank. It should hang straight from the handle with a little bit of slack. If it’s too tight, it can prevent the flapper from sealing properly, causing water to leak into the bowl.

A loose chain might not lift the flapper high enough to allow for a full flush. Adjust the chain length as needed by unhooking it and reattaching at a different link.

Look closely at where the chain attaches to both the handle arm and flapper. Make sure there are no kinks or tangles that could interfere with its movement. Replace the chain if you notice any signs of wear or damage that could cause problems in operation.

Properly connected and functioning chains help prevent intermittent running and save on water bills by ensuring efficient flushing action every time you press down on your toilet handle.

Replace the Flush Valve

Unscrew the flush valve from the tank with care. Take out the old valve and put in a new one. Make sure it fits snugly and seals properly, so water won’t leak. Use a wrench to tighten the valve, but do not over-tighten it; this could crack the porcelain.

Attach a new flapper chain to the flush lever arm. Adjust its length so that when you pull on the lever, it lifts up without any slack yet isn’t too tight to prevent sealing after flushing.

This step is crucial for effective flush mechanics and water conservation. Proper installation of the flush valve can help save on your water bill by stopping leaks efficiently.

Related Repairs: Fixing a Drip in Your Faucet

Get ready to stop that annoying faucet drip and save water! Fixing a dripping faucet is similar to repairing a running toilet. Both tasks help you cut down on water waste and lower your bills.

To start, shut off the water supply under the sink. This step is crucial to prevent any spills or accidents.

Next, take off the handle of the faucet by loosening the screw that holds it in place. Look for signs of wear on the washer inside—it’s often the cause of drips. If it looks worn out, replace it with a new one from your local hardware store.

Make sure everything fits snugly when you put it back together.

Check all parts while you have things apart; sometimes other pieces like O-rings need replacing too. Turn the water back on and test your work by turning on the tap—no more drips means success! Remember these tips next time you hear a telltale drip in your home.

When to Contact a Professional Plumber

Sometimes, fixing a toilet might need expert hands. If your toilet keeps running after these steps, call a plumber. They know how to tackle tricky issues and prevent future problems.

Remember, getting professional help can save you from water damage and high bills.

Take action today! Fix that running toilet and enjoy the peace of mind knowing you’re saving water and money. Don’t forget; for leaks you can’t fix, there’s always a professional waiting to assist you.

Frequently Asked Questions

Transitioning from knowing when to call in the experts, let’s tackle some common queries you might have. Got a toilet without a ball float or one with a button flush? No problem. Fixing these types isn’t as tricky as it sounds.

Replacing the fill valve in toilets without a ball float often solves running issues. Button flush mechanisms may need adjustment or change of the flushing system components.

Wondering about costs? Repairing a running toilet can vary in price. Simple fixes like adjusting water levels won’t make your wallet cry. But, if you must replace parts like defective fill valves, expect to spend more.

Keep in mind that fixing leaks quickly saves gallons of water and cuts down your water bill, making repairs worth every penny for long-term savings and environmental impact reduction.


Now you know how to tackle a running toilet with confidence! Follow these steps and use the right tools to sort out the issue. Think of the water you’ll save and the lower bills too.

Remember, check all connections and adjustments carefully. Get ready for a proper working toilet that’s both efficient and eco-friendly!


1. What causes a toilet to keep running, and how can I fix it?

A toilet keeps running often due to an issue with the fill tube or the float adjustment. You can fix this by checking both parts and making sure they’re set correctly for proper water level adjustment.

2. Can fixing a running toilet myself really save on water bills?

Yes, attending to your own toilet maintenance like leak detection can prevent wasted water, saving you money on your bill and reducing your carbon footprint.

3. Are there any tools I need for adjusting the float in my toilet tank?

To adjust the float in your toilet tank, you’ll usually just need a screwdriver. Some models may require no tools at all – check first then proceed!

4. After fixing my running toilet, why is it important to perform regular checks?

Regular checks ensure everything continues working properly which aids hygiene, stops leaks before they get big, and keeps down water usage impacting both your wallet and environment positively.

5. How do wet wipes relate to maintaining toilets and preventing runs?

Wet wipes don’t break down like normal tissue paper; they might block pipes causing more issues with flushing that leads to increased greenhouse gas emissions during repair work so stick with loo roll!

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