Skip to content

Help! My Toilet Won’t Flush, How To Fix It!

by | Mar 11, 2024

A hand on the handle of the toilet, trying to flush it.

We don’t think much about flushing the toilet until we can’t. It’s beyond frustration, and it’s a sanitation issue. The first thought of why won’t my toilet flush is always, “There must be a clog.” However, several things might cause a toilet to either not thoroughly flush or stop flushing.

Toilet flushing problems happen at home and in public restrooms. However, if plunging the toilet becomes a regular chore, then it might be time to replace some parts or the toilet altogether.

How a toilet flush works

  1. Handle: When you push the handle down, a lever is raised.
  2. Lever: The lever (a.k.a lift arm) pulls on a chain connected to the flapper valve.
  3. Flapper: The flapper valve, when opened, allows water from the tank into the bowl.
  4. Gravity and Siphon Action: The rush of water creates a siphon that pulls water from the tank and further flushes waste and toilet paper out of the bowl.
  5. Water Refill: Once the tank is empty, the flapper shuts. A float valve is triggered, allowing water to refill the tank. Once full, the toilet is ready for the next flush. 

Below are 8 possible reasons why your toilet won’t flush.

Water Supply

The toilet tank needs water to flush. If the water is not refilled, the flush can’t happen. The water supply is not typically the main culprit behind a non-flushing toilet. However, investigating the water supply is a great place to start.

Water Supply Valve

The water supply shutoff valve is located behind the toilet. Behind the toilet, you’ll find a flexible pipe that brings water to the toilet tank. Having this valve allows you to isolate the toilet’s water supply for repairs or maintenance without needing to turn the water off to the house.

This valve is usually in an open position. Remember “Righty tighty, Lefty Loosey.” To open the valve, turn it left. If the valve doesn’t turn left any further, it’s considered open.

If you think the valve is stuck, turn it right to see if it can open and close. Never force a valve to turn; if necessary, spay on some WD-40 for a moment and loosen it up before turning.

Water pressure

Low water pressure might prevent the tank from fully filling. If this happens, there might be insufficient water to create a proper flush. Low pressure might also not provide enough push to move the waste through the system.

Look for these signs of low water pressure:

  • Reduced water flow throughout the house
  • Appliance performance
  • Flushing issues

The ideal water pressure for a home is between 40-60 psi. A plumber can run a pressure test to see where your home is at and give further suggestions on how to improve this.

Flush Handle & Lift Arm

The flush handle and lift arm are responsible for unsealing the flapper. If the handle or lift arm gets damaged or broken, this prevents the toilet from flushing.

A Flush handle can be a lever, push button, or touchless. However, no matter the style, its function is to raise the lift arm. The lift arm is connected to the Flapper with a chain or a hook. It has the job of pulling up on the flapper, which unseals the tank from the bowl.

Here’s some things to look for

  • Loose connections
  • Bent or misaligned
  • Cracks
  • Corrosion
  • Disconnected chain or hook

Many times, if the issue is a loose connection, a misalignment, or a disconnected chain or hook, these can easily be fixed by tightening or reconnection. However, in the case of broken pieces or rust, it’s suggested to install new parts.


The flapper creates a watertight seal that prevents water from reaching the bowl until a flush is needed. When the lift arm pulls the flapper up, it becomes unsealed, allowing a flush. If the flapper is misaligned or has a buildup of minerals, it could prevent a flush from being successful. If you notice damage to the flapper, make sure to replace it.

Signs of problems with the flapper

  • Weak Flush
  • Running Toilet


The float or the fill valve’s function is to fill the tank with water. When the float literally floats on top of the water and when the water level lowers, the float allows water into the tank. Once the water reaches the desired level, it cuts off the flow, preventing the tank from overflowing.

An incorrectly adjusted float might not allow enough water into the tank. Therefore causing a weak flush. On the other hand, if the float gets stuck and isn’t allowed to rise with the water, the toilet might overflow, causing a flood. If you spot damage, make sure to replace it.

Rim Jets

Rim jets are those little holes at the top of the bowl. This is where the water flows from the tank into the bowl. If your home has hard water, then these might clog with build-up. These mineral deposits need to be scrubbed away. A reduction of water flowing into the bowl causes a weaker flush.   

The best way to clean mineral deposits in a toilet is to take a paper towel soaked in white vinegar and place it over the rim jets. This will keep the area saturated with the vinegar longer. Let that sit for 30 minutes to an hour, and come back to scrub with a cleaning pumas stone.

Low-Flush Toilets

First, traditional toilets use 3-5 gallons per flush. Next, we had low-flush toilets that used around 1.5 gallons per flush. Water conservation is excellent, especially living in a desert state. However, the earlier low-flush designs were not designed to be efficient with that water and very prone to clogs. Today, low-flush toilets are designed differently and work much better with more flushing power, 

Unfortunately, if you have one of the older low-flush toilets with consistent issues, it might be time to replace it. We’d be happy to help. 


Have you ever flushed, and the water started to rise rather than drain? It’s an alarming event that can cause panic! Waste, toilet paper, and other objects have the potential to block the passage between the toilet bowl and drainpipe. This restricts the water flow, which stops the ability to expel waste.

Signs of a clog:

  • Slow flush
  • Incomplete flush
  • Rising water levels
  • Overflowing toilet
  • Gurgling sounds

A plunger is your best friend when removing clogs. It forces water through, which most often dislodges the clog. If a plunger isn’t working I suggest calling in a professional.

Paper towels, feminine hygiene products, and kid toys should NEVER be flushed. 

Drain Line

The drain line is the pipe that carries waste away from the house and into the sewer or a septic system. If the drain line has a clog, you’ll know as there will be multiple draining issues, including sinks, tubs, and showers.

You can always try plunging, but if the problem is indeed the drain line, then a drain snake or (Auger) might be a better tool. This is a tool used by professionals to clear out more serious drainage issues. 

More Articles You Might Enjoy...

Alma Bradshaw

About The Author

Hello, My name is Alma Bradshaw. I'm a licensed plumber with over 20 years of experience in the industry. It's important to stay informed and up-to-date on the latest plumbing techniques, innovations, codes, and regulations. Learn more about plumbing here and feel free to comment below with any questions.

Sunset Plumbing logo for the footer

Sunset Plumbing Utah

1562 Evans St, Lehi, UT 84043

Sunset Plumbing

776 N 470 E Genola, UT 84655

Sunset Plumbing logo for the footer

Sunset Plumbing Utah

1562 Evans St, Lehi, UT 84043

Sunset Plumbing

776 N 470 E Genola, UT 84655

Check out our Reviews