How To Fix A Slow Flushing Toilet: DIY Guide


How To Fix A Slow Flushing Toilet Img

Proper flushing requires the quick flow of water from the tank to the bowl. This motion creates suction in the pipeline, which is how the flush works. So why does the toilet flush slow down? Well, there are multiple reasons why the flush might not work as it is supposed to be working. Thus it flushes water slowly. Such as:

Clogged mildly

Mild clogging (buildup in the J-shaped trap pipe or straight in the sewage line) can disrupt fluent water flow. Flushing undissolvable objects down the toilet are usually the cause of the mild clogging.

Tank setting issues

If the water supply and setting are too low in the tank, it may cause slow flushing. Because then it won’t supply the necessary amount of water for the flushing toilet work correctly.

Hard water supply

Hard water refers to supply water, which contains natural minerals like sodium, calcium or magnesium carbonates. These are harmless for the human body, but they can do immense damage to the pipeline and the toilet. These hard minerals can clog the holes under the rim.

Poor ventilation

Lack of proper ventilation in the pipeline causes a suction delay. Because the pine is not adequately pressurized to create the suction, thus the flushing is slow. Notice for a gurgling sound in the drain nearby while flushing the toilet. If you hear it, then poor ventilation is the cause of slow flushing.

Fixing slow-flushing process

Now, how can you fix the slow flushing toilet? There are a few ways to fix these errors and make the toilet flushing well-functioning again. There are a few basic remedies for solving the issue. But before trying to fix a slow flushing toilet, you must take some precautions.


  • Hygiene is our first concern. So before starting, you must put on gloves. Rubber gloves are the best for the purpose.
  • You must turn off the water supply of the tank.
  • You also wear a mask if you want. Mask is completely optional, but you can never be too careful, right? And finally,
  • Take the top off the tank with caution, without damaging any other parts of the flush valve.

Removing clogs

The clogged toilet is usually the leading cause of slow-flushing. The clogs can be in the j-shaped trap pipe, pipeline or the holes under the rim.

Removing solid waste

Partial waste blockage can be removed using a plunger. The continuous suction of the plunger will clear out the solid waste that clogged the line in the first place.

Firstly, fill the bowl halfway than usual, then place the plunger on top of the bowl and plunge. The water will create the vacuum it needs to unclog the pipe.

Note: Reducing water to half in the bowl will prevent unnecessary water splash.

Removing rim blockade

The pathway from the tank to the bowl contains several small holes that control the flow of water. These inlet holes can get clogged as well, usually by the hard minerals from the water. To clean these, you need a small toilet brush or straightened out paper clip, makeup or small bathroom mirror for better seeing under the rim and hard minerals removing substances (borax, vinegar, etc.) You have to scrub it off the inlet holes under the rim. Do not forget to turn off the water supply line of the tank.


To recover proper ventilation in the pipeline, you have to clear all the waste and dirt from the opening of the vent. Then pour water into it. If the water backs up, then the vent needs to be cleaned. You have to clean it with a sewer auger for a better and easier cleaning process.

Now, take the sewer auger and hold it firmly upside down on the opening of the vent. Then brush up and down all the way the auger can go. That would clean the vent and adequate ventilation would be restored.

Resetting level of water

The tank has a precise level of water containing capacity. A higher level of water creates uncontrollable overflow in the bowl, which is a wastage of water. And a low level of water is the cause of slow-flushing. Usually, the water level has to be about an inch below the top of the overflow tube when the tank is full. You can adjust the level by adjusting the float; it will make the fill valve stay on longer.

To adjust the float, you have to use the adjustment screw on the top of the fill valve. Turn the screw clockwise to rise the water level.

Note: Traditional toilet tanks may not have the adjustment screw. In this case, you have to replace it with a new fill valve.

Flapper check

The toilet flapper covers the drain in the tank. It controls the escape of water from the tank to the bowl. The flapper is linked to the flushing knob with a chain or rod. If the flapper is damaged, it will not flush smoothly because the flapper will not rise for long enough. The chain or rod that handles the water flapper opening between the tank and bowl gets displaced sometimes. It can be adjusted and added to a different link to fix slow flushing.

We need the flush to last longer. So, first of all, empty the tank, take the top off and carefully unhook the chain/rod from the end of the flushing knob. Now, put the pin down a few links towards the flapper and hook it to the flushing knob again. This will make the chain a bit shorter, which will help to hold the flapper open for a more extended period. This is how you can fix a slow flushing toilet.

Tips: Sometimes, pouring hot water directly in the toilet helps to remove clogging and recover the spontaneous flow of flushing. You need to be very careful while using vinegar and borax. Always wear rubber gloves and mask before using these chemical substances. For removing extreme clogging or removing tree roots from the pipeline (if there are trees planted in the ground near the lines or the drain), it is recommended that you hire a professional plumber.

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