How to Fix Toilet Not Flushing Strong Enough?

Your bathroom is a place of everyday comfort and convenience, so you don’t want to see it working slowly. A malfunctioning toilet interferes with your daily habits and wastes your time, especially when it can’t get rid of its content.

So what to do with the toilet that’s not flushing strong enough? The first task is to discover the problem as it may be a clog, a flapper chain, or something else. After that, you can focus on unclogging the toilet or fixing a different problem.

Experience taught us that eight things could cause a weak flushing toilet, so let’s go through each issue and learn how to solve it.

Problem 1: You Have a Low-Flow Toilet

A low-flow toilet is one of the most common reasons why you’re struggling with the weak flush. Low-flow toilets have the purpose of saving water, using 1.6 gallons per flush at best. 

It’s an eco-friendly design, but it also makes the toilet less powerful. Low-flow toilets can flush mildly for two reasons:

• You’re not pressing both buttons when flushing (you use half flush only)
• The system is set to reduce water consumption

Each of the two options has a unique solution, so let’s see how to deal with these problems.

Solution: Press Both Buttons or Strengthen the Flush System

If your toilet can’t dispose of waste because you’re pressing only one button per flush, the solution is very simple. All you need to do is press both buttons on your dual flush system.

This is important because half flushing can only eliminate liquids such as urine — it’s not the right option for harder waste, including human feces.

On the other hand, a default low-flow system forces you to roll up your sleeves. You can’t convert a low-flow toilet into a high-flow model, but there is a catch here — you can increase the flush power of your toilet.

Do this by checking the position of the tank float. The toilet float controls the water level in the tank, not allowing it to go above a certain volume. If it’s set too low, there won’t be enough water in the toilet to flush properly.

Lifting the float is simple:

• Remove the tank top with your hands
• Grab the float with your fingers (it’s a plastic ball, you can’t miss it)
• Lift it to stay a couple of inches below the tank lid
• Put the lid back on top of the tank

After doing that, the tank will start receiving additional water to flush the toilet with greater power.

Problem 2: Clogs in the Toilet Drain

A clog in the toilet drain is another common cause of weak flushing. Clogs in the plumbing system appear when various forms of waste stick to the pipes, preventing the usual water flow in the sewer system.

Toilet clogging is frequent when throwing non-flushable items like baby wipes, tampons, Q tips, nails, and hair. In this case, the outlet drain can’t digest too much water at once, so the flushing power appears weaker than usual. 

Solution: Unclog Your Toilet

The only solution to the clogged drain is to remove waste objects stuck in it. Use a plunger, a toilet auger (AKA snake), or liquid chemicals for this process. For example, this is how you can unclog a toilet with an auger:

• Push the auger into the toilet bowl with its corkscrew pointing downwards
• Start rotating the handle clockwise as it will help the tool go deeper
• Let the drill dive deeper into the pipe, but do it slowly to prevent cracks and scratches
• Once it reaches the clog, the auger will feel resistance and stop for a moment
• Now you can push it slightly harder to break the clog
• When it starts progressing again, you’ll know that it broke the clog
• Pull out the auger and clean it
• Flush the toilet to check its flushing power

Problem 3: The Chain Is Too Long

Every toilet has a flapper in the tank that controls the water flow after flushing. When you press the flush handle, its long arm pulls the chain holding the toilet flapper — that’s how the flapper goes up to let the water go down the outlet pipe.

But when the chain has too much slack, it prevents the flapper from staying up and delivering enough water to the toilet bowl. In such circumstances, the only solution is to shorten the chain — it will initiate the flush valve opening.

Solution: Shorten the Chain

There is a quick hack to solve this kind of weak or incomplete flush. Firstly, you can shorten the chain by removing a few links. It requires taking several steps because the chain is inside the toilet tank, covered by water:

• Close the shutoff valve behind the toilet (turn it clockwise)
• Remove the tank lid and flush the toilet to empty the tank
• Use pliers to detach a few links from the flapper chain
• When it’s short enough to work properly, you can reassemble the tank
• Open the water supply valve to let the water back in the tank
• Test the toilet by flushing it a few times

Problem 4: A Clogged Siphon Jet

A toilet siphon jet is a hole that you can see on the bottom of the toilet bowl. It’s pointing directly at the outlet drain, spraying the water, and pushing the waste out of the bowl. But if the siphon jet is clogged, the toilet loses power and flushes mildly.

Solution: Clean the Siphon Jet

The good thing about siphon jets is their position. The siphon jet is very accessible, so you can reach it with your hands and use common household items to clean the hole. 

For instance, a wire coat hanger can serve as a drill to break a partial clog.

• Bend the metal hanger to make a firm and sharp piece of wire
• Insert it into the siphon jet and start drilling
• The clog is probably near the exit, so you can break it with ease
• When you do that, use a toilet brush to clean the jet’s entrance
• Now you can flush the toilet — the clog is not there, and it should work well

Problem 5: Clogs in Rim Jets

Rim jets are similar to the siphon jet, and they fulfill the same purpose of cleaning the toilet while flushing. The only difference is their position because you can find rim jets right under the toilet bowl ring.

These small inlet holes are also prone to clogging, so you’ll have to clean them to dissolve the waste block.

Solution: Unclog the Rim Jets

Cleaning inlet holes is the same as unclogging the siphon jet. You can use a metal coat hanger to clean each hole, while the toilet brush helps you remove small waste remnants. If you unclog each hole, rest assured the toilet will flush powerfully.

Problem 6: Low Water Level in the Toilet Tank

Sometimes the water level in the toilet tank is not high enough to deliver strong flushes. As a result, the tank is not filling with water, and your toilet can’t handle toilet paper, urine, and hard feces.

Most times, the water level goes up near the top of the overflow tube. If that’s not the case, the tank and the bowl won’t get enough water to deal with whatever’s in the toilet when you flush it.

Solution: Increase the Water Level

The solution is almost always the same, and that is to raise the tank float. We explained this process while writing about problem number one, but here’s a quick recap:

• Remove the tank top with your hands
• Grab the float with your fingers
• Lift it to stay a couple of inches below the tank lid
• Put the lid back on top of the tank

There are rare occasions when homeowners put something in the tank to reduce water consumption. For instance, it can be a bottle of Fabuloso or even a brick. The goal is to prevent water from filling the tank, but it lowers the flush power.

In case you did this, the solution is straightforward — open the tank cover and remove the object you put in the tank. It allows more water to get into the tank while refilling, preventing a weak toilet flush.

Problem 7: Low Water Level in the Toilet Bowl

Sometimes the toilet bowl doesn’t contain enough water to ensure proper waste disposal, so you end up with a weak toilet flush. The problem usually occurs when the fill valve in the toilet tank isn’t working adequately.

Apart from the low water level in the toilet bowl, you can tell it by checking the fill valve itself. It is in the toilet tank next to the overflow tube — the fill valve is slightly higher than other parts. If you see it’s leaking while you flush the toilet, it’s broken.

Solution: Replace the Fill Valve

Before you start replacing the fill valve, you need to empty the toilet tank. We already explained how to do it, so let’s move on to the more important steps.

• Detach the old fill valve by removing it from the tank bottom
• Pick up the damaged fill valve and throw it into the trash can
• Insert the new fill valve into the toilet tank
• Make sure its top resides an inch or two above the overflow pipe
• Once the valve is set, you can install the lid and fill the tank with water

Problem 8: Clogs in the Air Vent

The air vent is on the roof of your house, but it still impacts toilet performance by balancing the drain pressure after flushing. A weak toilet flush might indicate a clogged air vent — it can clog due to leaves, debris, and bird nests.

Solution: Unclog the Air Vent

We recommend calling a licensed plumber to unclog the air went because the project is somewhat dangerous. If you still want to do it alone, remember to take precautionary measures and secure yourself while working on the roof.

After that, follow these steps to unclog the air vent:

• Put a garden hose on the entrance of the air vent
• Turn on the water and clean the vent pipe
• In case of backflowing, use a toilet snake to remove clogs from the air vent
• After unclogging, bring back the garden hose to clean small waste piles  

When you finish the entire procedure, the air vent should be clean and ready to work properly. It will balance the pressure in the plumbing system and prevent a weak toilet flush.

The Bottom Line

If your toilet is not flushing strong enough, the problem is likely a clog in the plumbing lines. Other possible causes of the weak toilet flush include low water levels in the tank/bowl, but it can also be the float position and the clogged air vent.

We showed you how to recognize a problem and how to deal with it in a step-by-step manner. Are you ready to give it a try? 

FAQ