Toilet Flushes Slow but not Clogged (causes & fix)

Flush is the most crucial part of any toilet. strong flushing toilet never comes under blockage issues, where maximum homeowner frustrated with a slow flushing toilet. 

So many people ask me why their toilet flushes slow but not clogged yet?

I had the same issue with my Kohler Tresham a couple of years ago. I tried every way to make my flush clear, but the methods did not work until I knew the exact reason behind it.

So, it’s essential whenever you fix something, make sure you understand the correct cause.

Toilet Flushes slow can many reasons like- the flapper seal, Chain adjustment, Most important Rim jet holes, Partially blockage between the tank and the bowl, New toilet’s tower flush valve and so on.

Today’s focus is on- Why the toilet flushes are slow but not clogged and how to fix slow and weak flushes toilets.

What is the Mechanism of Toilet Flush?

One toilet flushes depend on multiple factors like the flapper, overflow tube, refill tube, water pressure, ballcock, chain adjustments, and mostly the rim holes.

Once you press or push down the toilet lever/handle, the chain present in the tank lifts the flapper. The flapper allows the water goes down to the bowl through the flush valve.

At the same time, the refill valve fills the tank with water according to the water level. The mechanism of a toilet’s flushing is pretty easy, but it depends on various factors.

If each has some issue, suddenly you can recognize the flush problem, overflowing toilet, maybe the bowl does not fill with enough water, and so on.

Why Do Toilet Flushes Slow But Not Clogged? 

Toilet flushes get slow and weak for several reasons like- the Flapper seal, Gasket, Flush valve, Fill valve, Rim jets, etc.


Toilet Flushes Slow but not Clogged (causes & fix)

Reason1- Toilet Not Clogged but Flushing Slowly Due to FLAPPER

The flapper is a rubber or plastic material. It is responsible for stopping the water from leakage and also doing a great job when comes to flush mechanism.

Once the flapper lifts the water flow through the rims to the bowl and creates a siphon pressure, so all waste materials are gone.

While you have the toilet with a slow flush, but there is no clog. –Then the flapper may cause the problem.

If the flapper won’t open properly or is too heavy, the water present in the tank does not go away. Here you can notice the flush becomes slow.

Another point is- If there is a mineral deposit around the flapper, it can’t open much. Thus the result ended with a slow flushes toilet.


Reason2- Toilet flushes slow and weak because of the PARTIAL BLOCKAGE IN RIM JETS 

Do you know about rim holes present under the rim? The jets are responsible for carrying the water from the tank to the bowl.

We generally clean the toilet from tank to bowl but not clean properly inside the tiny holes. 

After a certain period, all holes become partially blocked by limescale. Due to the low cleanliness, they gradually reduce water carrying which results in a slow flushing toilet.

Read more- How to Clean Entirely Rim Holes 


Toilet Tank

Reason3- Slow flushing toilet because THE TANK IS NOT FULL ENOUGH  

The toilet tank is not full enough with water is another reason for the toilet flushing slow but not clogged yet.

Flush pressure increase by the water reservoir. If the tank is not full of water, it does not create the pressure required for flushing.


Reason4- No clog present still the flush slow due to THE CHAIN ADJUSTMENT

If you are sure there is no clog in the toilet, but the flush still becomes slow, another cause is the chain. The chain connects to the flapper seal through a chrome trip level. 

Because the loose chain can not open the flapper completely, enough water does not go through the bowl.

The chain is responsible for opening and closing the flapper as demanded. 


Reason5- No clog, slow Flushing toilet Because of New Toilet Tower Flush Valve

So many people suffer the same problem with their new toilet too. For a brand new toilet, we don’t expect any issues like slow flushing. 

It should work like a cyclone but not this case. Installation of a new toilet is as important as its other mechanism.

The tower flush valve is not secure properly- that’s why the new toilet becomes slow flushing, yet it is not clogged.


Reason6- THE FILL TUBE may be the cause for slow flushes toilet

The Fill Tube in a toilet plays a vital role in filling the toilet tank, maintaining the water level, and preventing overflow. 

Fill tube generally cracked the most and causes not filling the water tank. Relatively face slow flush.


How Do You Fix a Slow Flushing Toilet That Won’t Clog?


Step1- Check the Chain Lenth

Like as mentioned before, the chain is responsible for flapper closing. Look at the chain hook hole. Now put the hook one hole smaller than the previous position that it already has.

Now check how the speed of the flush has increased a little or not? If it grows a little, the hook is one more way forward.

Check again by flushing, then see if the water runs through the bowl on its own. If so, the previous hole was perfect- This is how the chain is adjusted.

The toilet flushes normally, after adjusting the chain position. You don’t need to do anything else unless you want to replace the flapper next.

Step2- Adjust the Flapper

A heavy flapper is mainly responsible for not opening completely. You can do it two ways- either change the flapper or add one floating ball next to the flapper seal.

For changing the flapper

  1. Buy the flapper according to the toilet model number or the universal flapper.
  2. Shut off the water line behind the toilet, turn it clockwise.
  3. Remove the lid from the tank and flush as much as possible.
  4. Remove the chain from the flush lever.
  5. The next step, pull the flapper from the pivot arm mount pegs on the overflow tube.
  6. Wipe off the seal on the valve seat to ensure a good seal.
  7. Next, line up your new flapper valve with the pegs on the overflow tube positioning, the flapper right over the drain.
  8. Clip the chain to the flush lever leaving some slack in the chain.
  9. Then, push down on the flush lever to make sure the flapper range of the motion is just right.
  10. You may have to adjust the chain length to get it right.
  11. Turn on the water line to turn it anticlockwise.
  12. Let the tank refill, the flapper valve seal should form a tight seal that prevents water from escaping the tank and draining into the bowl.
  13. Once you are satisfied that the flapper is not leaking, or has done a good job, place the lid in its place. 

Attached a Floating Ball

If your flapper is new and doesn’t want to replace another one, try this trick. Take an old ball that is floating or any Thermocol (polystyrene material) attached near the flapper chain.

These floating items help the heavy flapper open widely.

Step3- Help the tank Full

After being done with the above two methods, still not recover go for the fill tube.

The fill tube helps the toilet tank fill with water. If it cracks or is damaged by chance, you may have to replace it. 

  1. Buy a new refill valve, Shut off the waterline and flush the toilet to empty the tank.
  2. Remove the lid and ballcock. Then use an old towel or sponge to dry out the tank wall.
  3. Place a bucket below the fill tube line and screw down the fill valve’s mounting nut with an adjustable wrench.
  4. Carefully take out the fill valve.
  5. To prepare a new fill valve, adjust the height so that the marking on top of the new fill valve is at least one inch above the toilet overflow tube.
  6. Insert and place the new fill valve, tightening the lock nut below the tank. 
  7. Trim the refill tube reattach the ankle adaptor, and refill tube to the overflow pipe.
  8. Finally, reconnect the water supply line as the tank fills- check the water level, leakage, then flush once to check the flushing speed.

The best product for slow flushing toilet


Home Remedy For Slow Draining Toilet- Use Liquid Dish wash and Hot Water

Spill 2 to 3 cups of a liquid dishwasher into the bowl and take one gallon of hot water.

Pour directly into the bowl so it flushes away automatically. Hot water and dishwasher break down any partial clog gather in the drain pipe.

After that, the toilet becomes a fast flush.

How do I make my toilet flush stronger – Use Epsom Salt

Epsom salt is a great element used in the bath, enhance beauty. Now Epsom salt works for the toilet too.

  1. To achieve a better result, I propose taking the plunge only once.
  2. Pour one cup of Epsom Salt immediately into the bowl.
  3. Wait for the salt to turn bubbly and soapy.
  4. Water and dirt react with magnesium and sulfate.
  5. Allow it to sit for one and a half hours before adding hot tap water.
  6. It should be flushed.
  7. If you like, you can use two parts baking soda and one part detergent.
  8. Another efficient way for removing the object from the drain is to use soap.

Green Gobbler Ultimate Drain Cleaner

Green Gobbler Ultimate Drain Cleaner is the best clog cleaner. It is all in one pack from the kitchen sink to the toilet’s deep drain.

Green Gobbler make in the USA. It is a plant-based product, non-toxic to health, eco-friendly. 

Green Gobbler is the best alternative for a drain opener also non-inflammable.

Final Verdict- Toilet Flushes Slow But Not Clogged 

Slow flushing toilets are a major complaint in homes, so don’t be upset if you’re getting difficulty. Examine each of the factors mentioned in this blog post, even if none of them perform, consult an expert.

If your toilet generates peculiar sounds when flushed, such as gurgling, there isn’t sufficient airflow in your sewer waste pipes to allow water to move freely across valves.

Note that safety is paramount in any home improvement work. If you are unsure about work, it is advisable to delegate it to a true professional.

FAQs on Toilet Flushes Slow But Not Clogged

Are there any DIY solutions for a slow toilet flush?

DIY solutions for a slow toilet flush can include using a plunger to dislodge any minor clogs, cleaning the siphon jets or rim holes, and ensuring the tank components are functioning properly. However, it’s important to note that complex or persistent issues may require professional assistance.

Could the water level in the toilet tank affect the flush speed?

The water level in the toilet tank can indeed affect the flush speed. If the water level is too low, it may not provide sufficient force to clear the waste effectively.

Adjusting the water level to the recommended mark on the overflow tube can help improve flush performance.

When should I consider calling a professional plumber for a slow toilet flush?

If your attempts to resolve the slow toilet flush issue are unsuccessful or if you are unsure of the underlying cause, it may be best to call a professional plumber. They can assess the situation, identify any hidden problems, and provide expert solutions to restore optimal flushing performance.

Are there any common toilet tank issues that can cause slow flushing?

Common toilet tank issues that can cause slow flushing include a malfunctioning fill valve, a worn-out flapper valve, or a defective flush handle. These components can hinder the proper flow of water and result in a slow flush.

Can a partially clogged pipe cause slow flushing?

While a partially clogged pipe can contribute to slow toilet flushing, it is not always the sole cause.

Other factors, such as a malfunctioning flushing mechanism or low water pressure, should also be considered when diagnosing the problem.

Thank You

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