Toilet Troubleshooting

As a local plumber I’m often asked for toilet troubleshooting advice.

This can be pretty difficult over the phone and often leads to more questions.

It’ll take time to explain too. So skip ahead by clicking any of the questions below.

Why is my toilet leaking water?

Why is my toilet tank leaking water?

Why is my toilet flushing itself?

Why doesn’t my toilet flush right?

Why is my toilet making noises?

Why does my toilet smell?



I know! I know! “Man, I just want to fix this stupid thing so I can watch the game!”

Believe me, I understand! I’ll be as brief as possible. That being said, the toilet is a pretty simple machine that can be easily understood by reading Toilets – How they work & DIY Tips.

But let’s get to some simple problems and solutions first.

Toilet repair, DIY

Problems & Solutions 

In the following troubleshooting guide there will be a single problem with a number of possible reasons for the problem.

There will be solutions included with each reason.

Some will have links you can click on for a post that addresses that reason for the problem.

There will be a portion of that page that explains how to fix the problem step by step with a video at the end of each linked page.

Why is my toilet leaking water?

There are a lot of reasons why your toilet can leak water.

When looking for a water leak you always look above the leak. If you find more water look up further.

Keep looking until you don’t find water. Then  look down. It really is that simple. A good guide is Korky plumbing parts guide.

In the following list you’ll find all the reasons and how to fix them.

Wax ring replacement –

A leaking wax ring can be due to drying out from age.

They usually last 10 years or more though. They can also be caused by a loose bowl that wobbles or slips when sat upon.

If the movement is due to a cracked toilet flange you better call us to repair it.

Otherwise replace the wax ring. Then shim it if it’s wobbling. And caulk the toilet to the floor to prevent future slipping.

To learn how to do these things go to my post about How to replace a toilet.

Water shut off replacement –

Sometimes a water shut off leaks because the nut at the base of the handle, the packing nut,

has loosened and just needs to be tightened. But usually it’s because it’s old and needs to be replaced.

To learn how to do that read DIY – Replace faucet water shut offs.

Riser replacement-

The water line between the water shut off and tank is called a riser tube.

If it’s leaking and old I’d recommend just getting a flexible stainless steel one and replace it.

That should be pretty self explanatory. When in doubt, bring the part with you to the store.

Why is my toilet tank leaking?

If you’re tank is leaking it can be quite a few things. But none of them should be too hard to handle.

If you’re lucky the refill tube that connects the fill valve to the overflow tube of the flush valve has slipped off.

It adds water to the bowl during the flush cycle to clean and refill the bowl.

Simply reattach it. If not read on

Fill valve replacement –

If you’re not lucky it will be the fill valve is damaged and spraying while filling the tank.

You’ll need to replace it. To better understand the refill tube or replace the fill valve read How to install a toilet fill valve.

Toilet problems, DIY

Another reason I find is someone has replaced the flush valve without trimming the overflow tube below the handle.

If the water level is set too high or the flush valve has failed water will run out the tank handle holebefore going into the overflow tube.

Trim the flush valve overflow tube.Check out the post How to replace a toilet flush valve.

Replacement – 

Still another cause is the tank has cracked.

This can happen because someone damaged it or stress from overtightened bolts.

You’ll need to replace the toilet if that’s the case.

To learn how to do that read How to replace a toilet.

Flush valve replacement – 

A more involved cause for a leaking tank is the tank to bowl gasket has been compromised.

In that case you’ll have to replace it. But sometimes the tank to bowl bolts are just loose and need to be tightened.

In either case, go to How to replace a toilet flush valve to learn how to fix either of these issues.

Condensation –

Sometimes tanks sweat if you’ve had the house open during a humid day.

The water is cold and the tank starts to sweat like a glass of ice tea.

Shut the door and turn the air conditioner on. And wipe the condensation off the tank.

Why is my toilet flushing itself?

If you hear your toilet coming on by itself then you’re just hearing running water.

That could mean a few things.

Flapper replacement – 

The most likely reason is your flapper is old and needs to be replaced.

If you’re not sure, drop about 10 drops of food dye in the tank and leave it alone for and hour or two. Then check for dye in the bowl.

There are other reasons for dye to be in the bowl but usually it’s an old or damaged flapper.

Go to the post How to replace a toilet flapper to learn this repair.

Flush valve replacement – 

But sometimes the flush valve overflow tube can be cracked and leaking or the flush valve seat that the flapper sits on has a knick in it.

There have been times when the refill tube is pushed too far down the overflow tube.

This will cause siphoning from the fill valve.

To learn more about this check out my post How to replace a flush valve.

Water pressure regulating valve installation –

Occasionally the cause of the problem doesn’t call for a toilet repair.

Excessive water pressure can be so high that it overpowers the fill valve and forces it on.excessive water pressure

That can be the cause of a very high water bill. Better to install a water pressure regulating valve.

For that you should call us.

But for information about it go to Excessive water pressure.

Why is my toilet not flushing right?

This is one of the more vague questions. I’ll try to list the most likely first.

Fill valve adjustment – 

If you’re asking why your toilet doesn’t flush right, the most common reason is the water level in the tank is too low.

Adjusting the water level to just below the top of the overflow tube will fix that.

You’ll see how to do that in my post How to install a toilet fill valve.

Clogged bowl jet – 

If it’s an older toilet you could have a clogged jet.

The jet is the hole inside the bowl underwater that shoots water straight down the bowl drain.Clean a clogged toilet jet

It helps increase siphoning power. This will get clogged with urine salts. Just chisel them out with a short screwdriver.

Be careful not to damage the bowl.

Replacement – 

An older toilet, usually 15 to 20 years old or older, just won’t work well.

Neither will a poor quality one. In these cases you’ll need to replace it.

You’ll find instructions on how to this in my blog post How to replace a toilet.

Unclog the toilet or drain –

If the toilet is clogged it won’t flush right. But sometimes it’s a more serious issue like a clogged main drain or sewer.unclog a toilet with a toilet auger

If it’s clogged just unclog it with a plunger or toilet auger, as explained in my blog post How to unclog a toilet.

But if it’s a clogged main drain or sewer you better call a pro

But you’ll find information about how that’s done in How to unclog drains.

Why is my toilet making noises?

Noises when you flush are normal, obviously. But we all know what they’re suppose to sound like.

If you’re hearing noises that are out of the ordinary, then read on.

Fill valve replacement –

Normally a worn or damaged fill valve can make some loud humming noises.

In that case replace it by following the instructions in How to install a fill valve.

Water shut off replacement

If you’re water shut off valve is the older multi turn style it has a rubber seat.

That rubber wears out over time and can not only clog the water line but make some funky humming noises.

Replace them by following the instructions in  DIY – How to replace faucet water shut offs.

Water pressure regulating valve installation –

Excessive water pressure is very damaging to a plumbing system and it’s fixtures and appliances.

When it begins to fail it can shake the pipes like an earthquake or just hum.

Call us for a water pressure regulating valve replacement.

If you’re not sure what that is read Excessive water pressure.

Why does my toilet smell?

Jokes aside, this is a common problem. It’s not suppose to smell.

If it does, it smells like sewage. This is both unpleasant and unhealthy.

And it could leak to other problems. Get it fixed when you can.

Here are a few reasons for this problem.

Pull and reset the toilet – 

An old or damaged wax ring is common reason for a smelly toilet.

It’s not that hard to do either. If you want to learn how to read How to replace a toilet.

Dry trap –

A toilet has a built in trap to prevent sewer gas from getting into your house.

If you don’t flush regularly the water will evaporate and allow the sewer gas into your home.

But a clogged sewer or bowl will siphon that water out.

If your sewer is clogged you can read How to unclog drains but I’d recommend you call us.

A clogged bowl can be handled by following the instructions in How to unclog a toilet.

In Conclusion

I know this is a lot to read through. I’m going to try and streamline this later.

But there’s a lot to this stuff.

And with over 25 years in the trade I can tell you there are a few things I skipped because they’re so rare.

I really hope that this is helpful to you.

And I really hope that you’ll consider calling Advocate Master Plumbing.

No matter what the problem, I promise we can troubleshoot it.

If you’re still not sure, check out our 5 STAR Reviews from Google, Facebook and Yelp at the bottom of our website.

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