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Toilet Water Rises Then Slowly Drains: Reasons & Solutions

If you’re experiencing issues with rising toilet water and slow drainage, there are several common associated issues. Fortunately, these issues can typically be resolved easily. But let’s learn the causes first.

So, why does toilet water rise and then slowly drain? The most common causes are toilet clogs, drain blockages, and a decrease in tank water levels. Aside from these, you may encounter port clogs and rim jet issues, as well as a lack of proper ventilation.

The majority of the issues have simple solutions. To avoid complications, call a professional in serious cases. However, in this guide, an easy-to-follow solution manual has been included after each problem. This will enable you to fix the raised issues on your own.

toilet water rises then slowly drains

6 Reasons Why Your Toilet Water Rises Then Slowly Drains: With Solutions

Here, we have discussed the six common reasons why your toilet water may rise, and then drain slowly. Along with discussing the issue, we have also included a quick fix for every issue.

1. Toilet Clogs

A clog in the toilet’s plumbing is one of the most common reasons for toilet water to rise and drain slowly. When toilet paper, hygiene products, or foreign objects are flushed too frequently, they can block the toilet.


You can dislodge the clog with a plunger or toilet auger.

  • Using a toilet plunger, forcefully plunge up and down while making sure the seal is tight.
  • A toilet auger can be used if a plunger fails to remove a clog. Extend the cable into the drain, rotate it, and retract it to remove the obstruction.

2. Main Drain Blockage

A partially blocked toilet drain pipe or main sewer line can adversely affect the flow of water. And this causes the toilet water to rise and drain slowly. This may entirely block the water and waste from being mitigated in the most adverse situation.


Use a drain snake or plunger to clear the blockage.

  • The blocked drain should be gently pushed into with the drain snake. After a few pushes, the plunger will automatically clear the obstruction in the drainage system.
  • To dislodge and remove the obstruction, turn the drain snake in a clockwise direction while applying pressure.

3. A Reduction in the Tank’s Water Level

Low water levels in toilets can be caused by a variety of factors, the most common of which are faulty flapper valves and air in the water line.

The flapper valve, which is located inside the toilet tank, is an important component. Its primary function is to act as a seal, keeping water in the tank until the toilet is flushed. However, the flapper valve can become faulty or worn out over time.

The water flow from the tank into the toilet bowl is restricted if it does not lift completely or closes too quickly. Because of this restriction, water levels in the bowl are low, resulting in a weak flush or slow drainage.

On the other hand, low water levels in toilets are frequently caused by air trapped in the water line. When air enters the water supply system, it displaces water, reducing the amount of water that reaches the toilet tank. As a result, the water levels in the bowl are insufficient.

Air can enter the line as a result of problems such as a faulty fill valve or plumbing leaks. Proper sealing and airtight connections in water supply lines can keep air out while maintaining optimal water levels.


Check the water level in the tank and adjust the float mechanism or refill valve.

  • Initially, you have to check and fix the flapper valve in the toilet and also check if there is any air in the water line.
  • The water level can be raised or lowered by adjusting the float arm (the float is situated back in the toilet tank) or turning the adjustment screw.
  • By flushing the toilet, you can check that the water level is where you want it to be. Make further adjustments if needed.

4. Port Clogs and Rim Jets

Mineral buildup and debris can gradually assemble in the toilet bowl’s ports and rim jets. It restricts water flow and causes a rise and sluggish drainage.


Cleaning the ports and rim jets will help to resolve the issue. Follow the steps below to clean them.

  • Remove any debris or blockages from the ports and rim jets by cleaning them with a wire hanger. You can also use a toilet brush with stiff bristles.
  • Move the brush or hanger firmly back and forth inside the ports and rim jets to remove any buildup.
  • Rinse the toilet with water to remove any loose debris.

5. Defective Chain, Handle, or Flush Flapper

The flushing process can be hampered by a broken flush flapper, chain, or handle. When the flush flapper is damaged, the tank is unable to be properly sealed, which causes water leakage and ineffective flushing. This will cause insufficient water flow and a sluggish drain.


Check whether the mentioned parts are functioning properly and are aligned correctly. To get flushing back to normal, replace any broken components.

6. Lack of Proper Ventilation

A plumbing system that does not have enough ventilation may have uneven air pressure. As a result, the pipes experience suction or negative pressure. This low pressure may obstruct the regular flow of water and cause fixtures to malfunction.


Check the ventilation system, particularly the vent pipe, for any blockages or obstructions.

  • Find the roof’s exterior toilet vent, then access the vent pipe. Clear the area around the vent opening of any trash or obstructions.
  • To remove the obstruction, carefully push a plumber’s snake or a long, flexible brush through the vent pipe.
  • Run water through the vent pipe to make sure the obstruction is removed
reasons for toilet water rises  then slowly drains


Here are three questions and answers regarding the toilet water rising and then slowly draining problems.

Why is my toilet flushing slow even though it’s not clogged?

If your toilet is flushing slowly despite not being clogged, there could be a few reasons for this issue. One possibility is a partially closed water supply valve.

Check the valve located near the base of the toilet to ensure it is fully open. Sometimes, the valve may have been inadvertently turned, restricting water flow. By ensuring the valve is fully open, you can allow maximum water flow for a more effective flush.

Are rising water levels and sluggish drainage in a toilet harmful to your health?

Rising water and sluggish toilet drainage are primarily plumbing problems, but they can also harm your health. The standing water may serve as a haven for bacteria and other microorganisms, resulting in foul odors and the spread of diseases. In order to keep the bathroom environment clean and hygienic, it is crucial to address the issue right away.

How do I handle a toilet that is overflowing and spilling water onto the bathroom floor?

To stop the water flow, first, find the water supply valve near the base of the toilet and turn it off. Locate and close off the main water supply valve for your entire house if you can not find the valve, or it is not functioning.

Then, call for a plumbing or sewerage professional to resolve the raised issue.

Final Thoughts

The water rises and then slowly drains; this can happen with any toilet. However, there are remedies for this. Most often, it occurs as a result of our own errors, such as when we flush tissue, cleaning supplies, or trash down the drain or into the toilet.

However, it can also occur as a result of a broken handlebar, flash, or chain. We must regularly clean our toilets in order to prevent these problems.

The toilet, ventilation system, and drainage system all need to be cleaned. We also need to be cautious about the water level in the toilet. However, if the above-mentioned solution can’t resolve the issues, immediately call for a professional.