How To Detect And Repair A Leaky Toilet: Ultimate Guide

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Have you got a suspicious drip near your toilet? Maybe you are worried you have a leak, but you don’t want to spend out on a plumber when you can repair it yourself? If you think you are brave enough to tackle your own toilet troubles, then we are here to help! We want to give you some step by step instructions so you can learn how to repair a leaky toilet. 

Whether you have never picked up a wrench or you have renovated entire homes, not everyone is confident when it comes to plumbing. But by fixing your own leaky toilet, you could save hundreds of dollars on plumber’s fees. Let’s start by focusing at the basics of your toilet. 

Table of Contents

What Type of Toilet Do You Have?

Did you know that toilets come in many different styles and designs? That’s right, not all toilets are the same, and because of this, you need to identify what type of toilet you have before you go pulling it apart to try and fix it. Of course, the easiest way to tell what type of toilet you have is to look at the installation guide that came with the toilet. However, if you acquired the toilet with a new home or didn’t install the toilet yourself, then it’s unlikely you will have this. Instead, here are some ways you can identify your toilet type. 

Toilets are made up of two key components. One is the bowl where the waste is collected and flushed through to the waste pipe. The other is the cistern, which is filled with water and the flush mechanism that pushes the water into the bowl. Both of these components can be found on all toilets (although in some instances such as portable toilets and SaniFlo toilets, these components will look very different). 

The main difference between a one-piece toilet and a two-piece toilet is whether or not these two key components are fused together. In fact, a one-piece toilet is molded as a whole unit combining both the bowl and the cistern into one formed piece. As you probably will have guessed, a two-piece toilet comes as a separate cistern and bowl, which is assembled together and can be installed separately or together. 

The reason you need to find out which type of toilet you have in your bathroom is simple. With a one-piece toilet, there are fewer places for water to leak from. Therefore, if you have a one-piece system, you know that there are only two places that you need to look for a leak. The first is where the water goes into the cistern, and the second is where the waste leaves the bowl. Because of the single form molding, there are no other pressure points or opportunities for leaks. 

If you have a two-piece toilet, then there are a few other places where you might find a leak. For example, it could be where the cistern meets the bowl, it could be where the waste is attached, or it could be where the cistern is attached to the wall. There are a lot more places to check for leaks with a two-piece unit, but this doesn’t mean the job is harder, just that it takes a little longer to identify spots pending fixing! 

How to Repair A Leaky Toilet Step by Step?

Find the leak

As we have mentioned previously, there are several places to hunt for a leak depending on which type of toilet you have. If you are a user of a one-piece toilet, then your possibilities of a leak are reduced. You should start by checking the water inlet to the cistern to see if that is connected correctly, if not, then you need to check the waste pipe at the base of the toilet to see if that is the cause of the leak. If you have a two-piece toilet, you should start at the base of the toilet and work your way up. Check the waste outlet, then where the bowl and the cistern are connected, then the water inlet. By now, you should be able to discover the leak. 

Empty the cistern

You need to empty the toilet of all water and waste in order to deal with the leak effectively. To do this, you should shut off the water at the water inlet valve. A diverter on the inlet usually controls this, but if your system is quite old, then you might need to turn the water off at the stopcock, which can be found under your kitchen sink. Once the water is turned off, flush the system a few times until the cistern, and the bowl are empty. You will then be able to tackle the leak without making more mess. 

Seal the leak

Now that you have identified the leak and have emptied the system of water, you should be able to work on fixing the leak with less urgency and a better view. Depending on where the leak is will depend on what you need to do in order to seal or fix the leak. In some cases, it will simply be a case of tightening the inlet or outlet valves. In other cases, you might need to reseal a seal using either PTFE tape (also known as plumbers’ tape) or completely replace the seal. Occasionally seals will perish over time and, as such, will need replacing with newer, better-made seals. 

Test your system

Now that you have sorted your seal, you will need to test the system. This can be a tense time, so you might want to take it slow and pour a jug or bucket of water into the cistern rather than turning the water back on. Once your cistern has some water in it, flush the system and see if your leak is fixed. 

Reassemble your system

Now that you are confident that you have fixed the leak, it is time to put everything back together again. Make sure that you do any bolts that you have undone up nice and tight, so you don’t create a new leak. Also, make sure that when you turn the water on, you open the diverter fully to allow a full flow into the cistern otherwise it will take forever to fill. Finally, give your system one last test flush to make sure that you are happy with your work before you put all of your tools away. 

Problems to Look Out for When Repairing Your Leaky Toilet

If you took on board with the steps above, then you should hopefully have fixed your leak. However, there are some other problems to look out for when repairing your leaky toilet. 

A kinked water supply tube

Occasionally your water supply tube can become kinked when you reattach it. This kink can cause a blockage and prevent any water from getting into the system. If your water supply becomes kinked, then all you need to do is to take it off, straighten it out and reattach it. Depending on how long it has been kinked for, you might want to straighten it out using a long thin implement inside. If the kinks aren’t completely straightened out, this will affect how long your cistern takes to fill up and can hinder the pressure of the flush. 

Blocked fill valve

The water that is charged into your toilet isn’t always filtered and, as such, contains debris and limescale. When this builds up in the cistern, it usually blocks the fill valve. If you are finding that your cistern isn’t filling up as quickly as it should be, then take a look inside the fill valve to see if there is anything blocking it. It’s quite easy to clean these parts. You just soak them overnight in limescale remover. But if you don’t have the time, you can always pick up a new fill valve from the hardware store for under $20. 

Loose securing screws in the cistern

This is the most common toilet leak with two-piece toilets and is such a simple fix. The cistern sits on top of the toilet bowl and is attached using two screws. Occasionally these become loose or, if your toilet is very old, will rust away. Tightening these screws takes seconds and helps to seal the two pieces together so that they form a tighter bond. If your screws have rusted, then simply pick up some new ones from the hardware store or consider that maybe it’s time to invest in a new toilet! 

Perished waste seals

When your toilet was installed, it would have been connected to the waste outlet using a rubber seal. This seal is designed to fit snugly in between the waste outlet from your toilet and the main drainage pipe in your wall or floor. Of course, these seals don’t last forever, and as the years go by, they will perish and break up. Replacing these seals is not an enjoyable task, but while you’ve got your hands dirty, it is worth cleaning the waste pipe for any old waste that might be blocking up your system, and that could cause a problem in the future. 

FAQs About Leaky Toilets

“I don’t have a leak, but I can hear dripping. What Should I do?”

If your toilet is making a dripping noise, but there is no obvious leak, then there could be two places this drip is coming from. The first is the cistern, where the water isn’t coming into the system quickly enough. Look at the water inlet and check that it isn’t kinked and is fully turned on at the wall. The second is the ballcock. This is what keeps the water levels in check, and occasionally the arm of the ballcock can become stiff. Ensure that the arm is completely free-flowing so that it can accurately gauge the water level in the cistern. 

“Why won’t my tank fill with water?”

This is usually a problem relating to the water inlet pipe. Check that it is fully open, free from kinks, and also free from debris. There may be a build-up of limescale in there, and if that is the case, it will need replacing. 

“My cistern won’t stop filling; what do I do?”

This happens when your ballcock arm is stiff and isn’t gauging the levels of the water correctly. Turn the water off, empty out the cistern (by flushing the toilet a few times) and put some lubricant on the ballcock arm. When this feels free enough to move around, it should be able to determine the water levels and fill your cistern accurately. 

“My toilet has puddles around the base, could it be a leak from the bottom?”

The way that toilets are made these days means that it’s VERY unlikely that your toilet has a crack in the bowl or the base to leak from. Check all the pressure points that we have mentioned above to rule those out first. Then, empty the system and investigate. In some cases, you might want to buy some dye (or use food coloring) and add this to a jug of water. Put this into the bowl and see if the leak continues and where the brightly colored fluid is coming from. Then you will be able to see where the leak is. 

Replacing Your Leaky Toilet

If your toilet is leaking due to old age or too much wear and tear, then you might want to consider buying a new toilet. Luckily, there are many more new, water-saving options available on the market that are easy to install and less likely to leak. You can check some of those toilets out online today. 

Now that you know how to fix a leaky toilet, we hope that you will have confidence in your new-found skill. Performing DIY on your own home is a real sense of achievement and is something that will save you a fortune too. Remember that while a leaky toilet is fixable, due to age, it might be simpler to replace your toilet instead. But don’t worry! That is also another simple DIY task! 

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