How To Fix A Toilet Flush Step-by-step Like An Expert

Did you wake up in the morning and found out your toilet won’t flush? A toilet that won’t flush is a headache, particularly if you only have one toilet at your place and don’t even know what is causing the issue. And you may know how to clean your toilet and keep it smelling fresh, but one that doesn’t flush can drive you mad.

Woman flush toilet after use

As common as a problematic toilet is, you will be happy to know that there are various, simple DIY solutions to get it up and running again. In this guide, we are here to help you diagnose what is causing your toilet to malfunction and how to fix it step-by-step like an expert. Without further ado, let’s get started!

How does a toilet flushing system work?

Before you try to fix your toilet, it is important that you know how a toilet flushing system works. Your toilet flushing system has two independent mechanisms – a filling mechanism and a flushing one.

Filling Mechanism

The filling mechanism has two basic parts.

1. Shut-off Valve

The shut-off valve allows you to stop the water flow into the toilet’s flush tank so that you can easily make the repairs.

2. Float Valve

The float valve controls the water level in the cistern. When the desired level is reached in the cistern, the float valve will shut off the water. There is a float rod or an adjustable rack that is responsible for this. You can change the float position and lower the level or the water within the cistern if you want.

Flushing Mechanism

There are six parts within this mechanism.

Hand press a double push down toilet button

1. Flushing Control

There are three types of flushing controls.

  • Pull-up knob
  • Single push-down button
  • Double push-down button

These buttons or knob controls the release of the water into the bowl.

2. Overflow

Overflow is a mechanism that allows excess water to flow from the cistern directly into the bowl in case the float valve is malfunctioning. This keeps your bathroom from flooding.

3. Flushing Plug

This part of the mechanism is present at the bottom of the cistern. When the flushing valve/plug is raised, the water present in the cistern flushes into the bowl freely.

4. Flushing Valve Seal

This is the bottom part of the flushing plug. With the help of this seal, a watertight barrier is formed between the cistern and the mechanism

5. Plug Seal

The plug seal makes sure that when the flushing plug is closed, the cistern is watertight.

6. Bowl Seal

This seal is present under the cistern and makes sure that there is a watertight connection between the toilet bowl and the cistern. When you push the flushing control, the flush valve is lifted and the tank empties into the bowl

When the level of the water drops, the float valves go to the bottom of the tank and the float rod is no longer pressing against the valve. This causes the water to flow into the tank again and it fills up, ready for the next flushing operation.

Main reasons your toilet will not flush

There are various common reasons why your toilet won’t flush – it could be anything from the toilet being clogged to the level of the water being very low. Let’s take a look!

1. Clogged Toilet

This is one of the most common and basic reasons why your toilet isn’t flushing. If you throw too much toilet paper or flush anything other than that down the toilet, it can clog the pipe. Most of the times, sanitary napkins and baby wipes are the common culprits behind toilet clogging. If you can’t unclog the toilet yourself, you can contact your building handyman or a plumber.

Young woman using plunger to unclog a toilet

2. Low Water Level

If the level of the water in the tank is too low, your toilet won’t flush. Usually, the level of the water in the tank needs to be 2cm below the top of the overflow. Check the level of the water and see if the water valve has been accidentally shut off to result in low water levels

3. Warped Flapper

Another reason why your toilet won’t flush is that the flapper is warped or bent. Remove the lid of the toilet tank and check the rubber flapper. It ensures that when you flush, the water is released and then close the water intake hole so that a sufficient amount of water remains in the tank. A bent, warped, or deteriorated one can result in a malfunctioning toilet.

4. Malfunctioning Lift Chain

At times, the lift chain which connects the flush handle and the flapper stops working properly. This happens when the chain has too much slack and isn’t able to raise the flapper, which results in common problems with flushing. 

How to fix a toilet that doesn’t flush

Once you know what is causing your toilet to malfunction, you can go about fixing it. 

1. Clogged Toilet

If your toilet is clogged and there is a blockage, use a toilet auger or toilet plunger to push the waste through or create enough suction to dislodge the waste blocking the toilet and allow it to move down the drain. 

2. Low Water Level

If you checked and the water level was low, it is probably because the water valve was accidentally off. Turn it back on and ensure that your tank fills up to the desired level. Once the tank fills up, flush the toilet to see if the problem was fixed.

3. Old Flapper

If it was bent out of shape, you can buy one from the local hardware store or any home improvement store. Turn the water off and drain the tank before you replace it.

A hand in orange gloves repair old flapper toilet

4. Issues with the Lift Chain

To solve the issue with the lift chain, all you need to do is adjust the chain length. Shorten the length of the chain and remove the excessive stretch. Ensure that it provides enough pull to raise the flapper off the overflow. 

Main reasons your toilet won’t stop running

See a sudden spike in your water bill? You probably have a toilet that is wasting large amounts of water. This means that the toilet is unable to maintain a stable water level in the tank. If it keeps running, then you may have one of the following issues.

  • Incorrect float height
  • Leaking flapper
  • Long refill tube

1. Incorrect Float Height

After you flush the toilet, the tank fills back up with the water to a certain point determined by the float ball. If the height of the float valve is incorrect, the water keeps leaking into the bowl. 

2. Leaking Flapper

A leaking one is a common cause of the disaster. It seals the water in the toilet cistern. Typically, when you flush, the it rises up and allows the water to move to the toilet bowl. Then, it drops back down and reseals the tank. However, if the flapper is broken or leaking, the water will keep seeping through it. 

3. Long Refill Tube

If your refill tube is too long and isn’t adequately positioned in the overflow tube, it will keep on pumping water into the toilet bowl. This is because the refill valves create a suction effect that pulls water down.

Step-by-step guide: How to stop a running toilet

So, are you ready to learn how to fix yours like an expert? Here’s what you need to know:

Man trying to fix toilet flush

Things You Will Need


Correcting the Float Height

  1. Turn off the water supply.
  2. Drain the water tank.
  3. If the float height is incorrect, you have to adjust its height
  4. If your toilet has a float arm, take a screwdriver and loosen the screw till the float gets in place.
  5. In case of a column float that has a fill valve, simply loosen the screw and push the float down to the height you want and then tighten the screw again.

Fixing a Bad Flapper

  1. If you continue hearing water running in the toilet, give the handle a little jiggle and see if the water stops running for a while. If this is the case, your flapper is leaky.
  2. Remove your old one. You won’t need any tools to do this as it is a fairly simple process. 
  3. Attach the new one and close the tank lid.

Shortening the Refill Tube

  1. If the issue still isn’t resolved, you will have to shorten the refill tube.
  2. Pull the refill tube out of the overflow.
  3. Hold the tube above the opening of the overflow.
  4. Trim the remaining refill tube off and clip it to the side of the overflow.

A working toilet is a necessity for all of us and sometimes, due to our own actions or faulty flushing mechanisms, it stops working and becomes a constant source of headaches for you.

Hand using toilet flush

A running toilet not only raises your water bill but also wastes precious water that can be used for other purposes. It is very easy to fix yours and not get a new toilet, if you know what the issue is in the first place. The DIY steps that we have mentioned above will help you get your toilet up and running again. Here’s to your working toilet, folks!

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