Top 7 Dual Flush Toilet Problems With Instant Solutions

The dual-flush toilet systems are deemed to be the most efficient flushing systems. As the name suggests, there are two different flushes. The small one is for liquid waste. It does not require too much water. And the large one is solid waste which needs all the water available in the tank.

Although these systems are great for conserving water, they are as susceptible to problems as regular toilets. And if you are looking forward to getting one of these toilets, you should have a fair idea about the common dual flush toilet problems. Otherwise, you might be caught off-guard when an issue occurs.

The good news is that you found the right source to know all about these toilets. All you need to do now is go through all the things that I have to share!

How Do Dual-Flush Toilets Work?

Basically, the dual-flush systems set themselves apart by offering two different flush methods to the users.

The button that you will find on the top will be separated into two sections. Depending on the model of the toilet, these sections will have varying sizes. But generally, there is a small part and a large part. Mostly, the small button will release around 3 liters of water into the bowl.

On the other hand, the large button will usually release 6 liters of water. And as I mentioned in the beginning, the small one is for liquid waste, while the large one is for solid waste.

Now, the way how dual flush toilet work is by depending on two different valves. They are connected with each other, which enables the user to use the right amount of water.

Common Problems With The Dual-Flush Toilets

If you want to go green, installing a dual flush would be the right move. You will not only make an environmentally-friendly decision but also can save on the water bill. However, these high-tech toilets have some issues that you need to be aware of. Allow me to walk you through the most common ones:

1. Clogging

Plumbers get a lot of complaints about clogged dual-flush toilets. But that does not mean that these toilets are actually prone to clogging. In most cases, these will clog only when you do not press the right button. Yes, even the best dual flush toilet will clog if you do not use it correctly.

The thing is, not everyone knows about these toilet types. As a result, they will press the wrong button while flushing. However, occasional clogging for pressing the wrong button is not something that you need to worry about. But if the problem occurs frequently, you might face major plumbing issues in the future.


Put a tiny label on each button to avoid pressing the wrong button. If you are wondering how to install toilet labels, you can just use a piece of paper and some glue.

2. Fill Valve Problems

The Cistern fill valve is the most crucial component of the toilet. And if any of the flaps start to wear out or break, you will face a water trickle problem. The thing is, when the flush starts to wear down, it can not gauge the water level accurately. As a result, overflow of water in the tank becomes a regular issue.

Now, when the water overflows the tank, you will be wasting a lot of water. These tanks will fill up 6 liters of water in most cases in 3 minutes. Considering that, you could be wasting 120 liters in an hour if you ignore the issue.

You may check the reviews on Best Toilet Fill Valve


It is a great idea to regularly check the water supply. See if there are signs of things wearing down. Also, you should check if anything interferes with the seal. But when your tank still leaks, you might want to check for foreign materials inside. They can hinder the optimal operation of the tank.

3. Cleaning Issues

Dual-flush models retain less water inside the bowl. This trait can make cleaning a bit tricky. With less water, you are more likely to accumulate filth quickly during cleaning. That will require you to flush multiple times, making you use too much of the cleaning liquid.


To tackle this problem, you should clean the toilet bowl frequently. That will lower the chances of arrogant filths settling on the surface.

We recommend to read the article on: How To Clean Toilet Tank Perfectly

4. Plumbing Compatibility Issues

Modern flats and homes are built to accommodate low-flush toilets. However, the old homes are meant to have high-flush toilets. In other words, you might face issues while installing a dual-flush toilet in a relatively old home.


Before you get a dual-flush toilet, make sure to check whether the plumbing system is compatible or not. If not, you should make some modifications. But if that is not possible, you should get a regular high-flush toilet instead.

5. Toilet Button

Just like regular toilets, dual-flush toilets will have springs on the button. And these springs can corrode and catch rust over time. Eventually, they will get a little stiff and might not work properly.


It is pretty easy to find a replacement button for the dual-flush systems. And replacing the button is a simple task as well.

6. Expensive Parts

The replacement parts of the dual-flush toilets are relatively expensive. At least they cost more than regular toilets. Also, the repair cost is a bit higher than normal toilets as there are two mechanisms to take care of.


To make sure that the toilet lasts for a prolonged time, you should maintain it regularly. That will lower the chances of the parts wearing down quickly.

The Dilemma

When someone first sees two buttons on top of the toilet tank, they can find themselves scratching their heads. It is not really that easy to understand which button to press.


The easiest solution to help people flush the toilet would be to put a label on the button.

Final Words

So, the major dual flush toilet problems that you need to be aware of are clogging, main valve, compatibility, and cleaning issues. But as you can see, there is a simple solution for each of the problems. Therefore, you should not really think twice about getting one of the dual-flush models and being environmentally friendly.

Hello, I'm Jon C. Brown, an expert in the field of toilets. With over 15 years of experience in this industry, a significant portion of my life has been devoted to crafting high-quality toilets and bathrooms. Consequently, I've received countless inquiries about the toilet and bathroom industries. That's why, I've launched this website to provide top-notch solutions for all your toilet and bathroom related needs.

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