All Blog Articles

Toilet Won’t Flush All the Way? A Florida Plumber Explains Why

If your toilet doesn’t fully empty its...contents when you flush, it’s not just gross, it’s wasteful and annoying.

So let’s see if we can’t help you determine the problem and solve it quickly.

If your toilet isn’t flushing all the way, it’s most likely because of one of these problems:

  • The water level in your toilet tank is set too low
  • Problems with your flapper
  • A clog in the toilet, flange or drain
  • Blocked inlet holes
  • Poor toilet drain pipe design

Yeah, that’s a lot of possible scenarios. 

But don’t worry, we’ll explain each issue and how to solve each of them.

Don’t care about the cause? Just want it fixed ASAP? If you live in the Southwest Florida area, just schedule your appointment with PlumbingToday.

The water level in your toilet tank is set too low

Your toilet needs a lot of water delivered quickly for a “successful flush.” But if the water level in your toilet tank is set too low, your toilet bowl won’t get as much water as it needs once you flush.

Manufacturers usually leave a mark on the inside of the tank to show you how much water the tank is designed to receive. That line is usually about an inch under the top of the overflow tube.

So why would your water level be set too low?

Well, some people manually adjust the level to save water. In other situations, though, some of the components in the tank may be misaligned and preventing enough water from filling the tank.

What to do:

If you’ve checked the level of your water and determined that it’s too low, you’ll want to adjust your float.

If your toilet has a large rubber ball device, this is your float ball. It floats upwards as water rises in the tank. As it rises, it closes off the water flow into the tank. So, try making a slight upwards bend in the arm of the float ball. The higher the position of the float ball, the more water is allowed into the tank. 

If your toilet has a floating cup ballcock, this is what you’ll see instead of a large rubber float ball.

These floats have a float adjustment screw on top of the fill valve, in which case you can turn the screw clockwise to raise the float.

Problems with your flapper

Your flapper is that small rubber seal that covers the hole in your toilet tank. 

When you flush the toilet, you’re actually lifting a chain that’s attached to the flapper. When that chain lifts, it lifts up the flapper which allows all the water in the tank to pour quickly into the toilet bowl.

When the toilet isn’t in “flush mode” the flapper’s job is to seal off that hole completely so that water doesn’t escape the tank.

But if the flapper is old or damaged or that chain isn’t set to an appropriate length, water will slowly leak out of the tank. And this decreases the amount of water available when you need to flush.

What to do:

First, check the length of your flapper chain. Make sure there isn’t too much or too little slack in the chain. If the length needs to be adjusted, remove the chain and re-hook it to a hole that is closer or farther away from your flush lever. Your chain should have about ½ inch of slack.

But if the chain has an appropriate length, check your flapper. If it’s old or cracked, you’ll need to replace it. If you’re up for the challenge, here is a great video detailing how to replace your flapper on your own.

Otherwise, you’ll want to hire a plumber who can replace your flapper for you.

A clog in the toilet, toilet flange, or drain

If you have a clog anywhere in the system, this will prevent water from fully flushing down the toilet.

Depending on where the clog is and how severe it is, you’ll either be able to remove it on your own or you’ll need help from a professional.

What to do:

First, try unclogging the toilet on your own. For instructions on this step, check out our article, “How to Unclog a Toilet”.

If your toilet still isn’t flushing completely after this, there may be a clog in the toilet flange or drain, which will require a professional.

Blocked inlet holes

Your toilet’s inlet holes are located just under the lip in your toilet bowl. When the toilet is flushed, water pours from these holes. So if they’re clogged you lose a good amount of water, which can prevent the toilet from flushing.

You can tell that they are blocked or clogged if there is no water streaming from the sides of the bowl or if that water streams straight down instead of diagonally.

What to do:

Hold a small mirror under the seat of the toilet and examine the inlet holes. 

If they’re clogged, follow these steps:

  1. Heat up 10-12 ounces of white vinegar (to at least 120 degrees)
  2. Using a funnel, pour the hot vinegar down your overflow tube 
  3. Let it sit for at least an hour (overnight is best) without flushing
  4. Then, use a small allen wrench or piece of wire to clear the inlet holes

Need help? Here’s a video showing you exactly how to clear clogged inlet holes.

The inlet holes can become clogged from bacteria or from mineral deposits. Both are often recurring problems so you’ll need to check for clogged inlet holes periodically. 

If your inlet holes are frequently clogged with light colored (almost white) material, you may want to invest in a water softener system to prevent mineral deposits and other problems caused by hard water.

Poor toilet drain pipe design

If your toilet has always had a slow flush, your problem is most likely an issue with the way your toilet drains were installed or designed.

You see, toilet drains need to have a downward slope in order for the wastewater to flow quickly down the toilet bowl, through the pipes, and into the main sewer line.

If your drains don’t have that downward slope, you’ll get a pool of water in the pipes that basically gets “stuck”. So, when you flush, your toilet water hits that “stuck” water and stalls.

What to do:

Have a professional plumber inspect your drain pipe systemand redesign if necessary.

Need help from a professional?

If you’ve tried everything but your toilet is still giving you a half-hearted flush, we’re here to help.

If you live in the Southwest Florida area, schedule your appointment with PlumbingToday.

Related reading: