Reasons Your Toilet Won't Flush & Ways to Fix It!

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If you’re known as the handyman around your house who your spouse, kids, or roommates come to when there’s a plumbing problem, chances are that you’ve heard “the toilet won’t flush” a few times (usually followed by “but it’s not my fault!”).

Trying to figure out the problem preventing a toilet from flushing properly can be frustrating if you don’t know what you’re looking for. That’s why we decided to share the most common reasons for a toilet being temporarily unable to flush and how to fix them yourself.

The following are the top reasons your toilet won’t flush and how to fix the issues.

The Toilet Is Clogged

Problem: Using too much toilet paper or attempting to flush anything other than toilet paper down the toilet can clog the pipe and make further flushing impossible. Sanitary napkins are a common culprit behind clogs like this.

Solution: Use a toilet plunger or toilet auger to push waste through and allow the toilet to flush. Alternatively, use the plunger to create suction that will help dislodge paper waste blocking the flushing action and allow it to move down the pipe. If you’re experiencing frequent clogs, you may want to consider using a thinner type of toilet paper, particularly if you or other household members use a lot in one sitting.

The Water Level in the Tank Is Too Low

Problem: The water level in a toilet’s tank should be approximately one inch below the top of the tank’s overflow tube. If the water in the tank is too low, check the water valve, as it may have been accidentally turned off.

Solution: If the water valve is off, turn it on and monitor the water level in the tank to ensure that it refills to the correct level, then flush the toilet to make sure it’s flushing properly again.

The Flapper Is Bent or Warped

Problem: Remove the toilet tank lid and inspect the rubber flapper. The rubber flapper releases water when the toilet is flushed and closes the water intake hole afterward so that the proper amount of water remains in the tank. If the rubber flapper on your toilet appears to have deteriorated or is too warped, bent, or misshapen to seal the flush tube hole, you’ll need to replace it.

Solution: Flappers are inexpensive items found at any hardware or home improvement store. Turn off the water and drain the tank before swapping the old flapper out for the new one, then try flushing the toilet again to ensure the problem is resolved.

The Lift Chain Isn’t Working

Problem: Sometimes, the lift chain, which attaches the flapper to the flushing handle on the outside of the toilet, can have too much slack and make the handle unable to raise the flapper and thus flush the toilet.

Solution: To solve this problem, you need only adjust the length of the chain to shorten it so that the chain can provide pull sufficient to raise the flapper off of the flush tube and allow water to flow when the handle is pulled.

The Water Supply Valve Is Clogged or Partially Closed

Problem: Before diving into anything else, make sure your toilet’s water supply valve is fully open. This valve—usually located near the toilet’s base—controls how much water flows into the tank after each flush. If it’s even slightly closed, your tank may not refill completely, which leads to a weak or incomplete flush.

Solution: Turn the valve counterclockwise until it’s completely open. Once the tank fills properly, test the flush again.

The Rim Jet Is Blocked

Problem: The rim jets might be clogged if your toilet is technically flushing but sluggish and doesn’t clear the bowl effectively. These small holes under the rim, along with a larger siphon jet at the bottom of the bowl, release water by forcing it to push waste through the drain. Hard water deposits or grime can block these openings.
Solution: Use a toilet brush and vinegar to scrub under the rim and clear any visible buildup. For tough blockages, fill the rim jets with vinegar and let them soak overnight before scrubbing again.

The Float Is Damaged or Obstructed

Problem: The float inside your tank rises with the water level and tells the fill valve when to stop. If the float is stuck, misaligned, or damaged, your tank might not be filling with enough water to flush properly.
Solution: Check that the float can move freely. Adjust its height according to the tank’s fill line. If it’s damaged or cracked, it’s best to replace it.

The Fill Valve Is Faulty

Problem: The fill valve controls how quickly and how much water enters the tank after each flush. It can wear out, clog, or stop working. This issue can result in long refill times or a tank that never quite fills up.

Solution: First, check for mineral deposits or debris and clean the valve thoroughly. Adjust the attached float if the water level is too low. If cleaning and adjustments don’t fix the issue, replacing the fill valve is usually a straightforward DIY project.

The Overflow Tube Is Cracked or Broken

Problem: The overflow tube inside the tank helps safely direct excess water into the bowl. If this tube is cracked, it can cause the tank to drain prematurely, preventing it from holding the amount of water needed for a complete flush.
Solution: Small cracks may be patched temporarily using a waterproof epoxy, but replacing the overflow tube is the more reliable fix in most cases.

When to Call a Plumber for a Toilet That Won’t Flush

If you’ve already tried the standard fixes—checking for clogs, adjusting the float, inspecting the flapper, and confirming the water valve is fully open—but your toilet still won’t flush correctly, it might be time to bring in a professional. Persistent flushing problems often point to issues that aren’t visible without the right tools, like blockages deeper in the drain line, sewer line backups, or issues with water pressure coming into your home.

It’s also worth calling a plumber if:

Your toilet clogs frequently, even when used normally
Water overflows or leaks from the base
The tank takes a long time to refill or never fills completely
You notice bubbling or gurgling sounds from nearby drains

A plumber can do more than fix the immediate issue—they can inspect your system, identify hidden problems, and confirm that everything works as it should. That’s especially important if you’re dealing with older plumbing or have already spent time and money on DIY fixes that haven’t worked.

Calling a plumber can also save you from unnecessary guesswork and prevent accidental damage. Instead of replacing parts that aren’t the problem or hoping the issue goes away on its own, you get a clear diagnosis and a durable solution.

Bottom line? If your toilet’s still acting up after you’ve gone through the checklist, it’s perfectly okay—and often smart—to call in a pro. You’ll save yourself time, stress, and the risk of turning a minor problem into a plumbing emergency.

If you’ve tried everything and still can’t flush your toilet, call R.S. Andrews at (470) 264-8128 and pass the problem off to our plumbing technicians who’ve been keeping things flowing smoothly in Atlanta for over 40 years. Let us handle the dirty work—you’ll be glad you did!