Dual Flush Toilet Not Flushing Completely

Dual Flush Toilet Not Flushing Completely

A dual-flush toilet employs two buttons or a lever to flush varying volumes of water. A tiny amount of water flushes liquid waste, and a considerable amount flushes solid waste. Installing a dual flush toilet in your house saves water and helps you become more eco-friendly. Double flush versions can cut water use by 60-80% without compromising performance.

But, like any toilet, dual flush versions have issues that prevent them from performing correctly. Knowing possible matters why your toilet not flushing completely, can save you money and time by reducing the need to employ expert plumbers.

Some common causes with solutions:

To fix a toilet that won’t flush correctly, find the cause of the issue. Finding a solution is usually straightforward if the fundamental cause is identified. Here are some common reasons why toilets don’t get fully flush.

A Blocked Sewage Pipe:

Blocked Sewage Pipe


A toilet waste pipe is required to remove waste and water from a toilet bowl. You’ll know if the waste pipe is full. Flushing removes debris from the bowl and quickly refills the tank. Even if the waste pipe is blocked, a weak flush and slow drain may suggest that you are partially closed.


Look at the mattress first. Water breaks down whatever is clogging the waste pipe with each plunger movement. To open the toilet, put a flange extension on the rubber portion, like this one from Amazon. They may be used in your toilet without flange extensions, although designed for shower drains only.

If drowning fails, toilet snakes can help you with that. Debris can be broken or collected using wires that reach deep into the pipe system, taking the approach down. If you don’t already own one, this is the best-selling toilet snake on Amazon.

The Jet Flush Hole (Siphon Jet) Is Clogged:

toilet flush hole


This basket keeps water in front of the toilet and lowers it at an angle so waste may be flushed straight into the drain. Calcium and other deposits can clog jet flush holes and reduce flushing power.


After using acidic toilet cleaners, use a brush to clean jet flush holes. To thoroughly clean the holes, insert a tiny brush and spin it many times.

Rim Jets Clogged:


When you flush your toilet, water is pushed into the bowl by rum jets. Both flush holes and rim jets can collect debris over time, block water flow, and lower flushing efficacy. Water should flush faster and harder than rum jets. Unless that happens, it’s time to go.


The best approach to clean rum jets is to use an acidic toilet cleaner in the overflow tube. After a few minutes:

  1. Rinse each spray with warm water.
  2. Dissolve.
  3. After a few hours, remove the plumber putty and flush.

Remove any leftover residue with a brush.

Related: Best Flushing Toilets

There is not enough water in the tank:

water in toilet tank


Insufficient water in the tank causes improper flushing, and the risk of blockage increases when the water level is low. If your tank has less water, the toilet will probably not flush correctly.


Each toilet tank has a float to adjust the water level. Place the float in the water and leave it there until you need it. When you flush the toilet, water drains the tank and drips down to open the flow valve. The float increases with the tank’s water level, and it shuts when the float reaches the desired height.

The float’s height alone can change the tank’s water level. Almost every toilet has a screwdriver-adjustable adjustment screw. To increase the amount of liquid in your tank, adjust the float to enter more water before the water is cut off. If your tank is full, turn the float counterclockwise to stop the fill valve.

There is not enough water in the bowl:

water in toilet bowl


The water in your toilet bowl will not flow properly if it is too low. The entire valve device in the tank may be causing the low water level in the bowl. If the total value splits and water seeps out, the water pressure in the toilet bowl is reduced.


Replacement of the malfunctioning fill valve equipment is a straightforward solution. Putting this method into reality might be challenging if you’ve never done it, and it’s best to learn by doing.

Remove the tank cover and flush a few times to see whether the water level in the bowl is too low. A leak is visible from the top of the fill valve. If you can’t figure out what’s wrong, I recommend hiring a plumber.


So there you have it: the most prevalent concerns with dual flush toilets. Most of these issues are improbable with a new toilet, and they can appear over time depending on how much you flush, maintain, and serve them. Every toilet has issues at some point, but being aware of them and how to deal with them will assist you.

Leave a Comment

Your email address will not be published.

Scroll to Top