Why is My Toilet Leaking From the Bottom? – 5 Causes

Written by

Paulk Webb


Freddie J. Hagopian

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why is my toilet leaking from the bottom

A leaking toilet is troublesome. If left unaddressed, the fault could cause serious damage to your toilet and its surroundings.

Fret not, however, because we have the answer to your query, “Why is my toilet leaking from the bottom?” The most common causes are condensation accumulation, loose bolts, a cracked toilet, impaired wax rings, and a loose water supply line.

Why Water Leaks From Bottom of Toilet


There are various reasons why there is a puddle of water coming from underneath toilet. The reason could be a faulty component of your toilet or an external factor.

Either way, these problems are easy to fix, and you may not have to call a professional plumber.

List of Causes


1. Condensation accumulation

Condensation occurs when the water vapor in your toilet is converted into liquid. You’ll notice your toilet looks like it’s sweating when this happens. When left unchecked, the water will build up at the base intermittently and can harm the floor and parts under your toilet.

To alleviate this issue, consider utilizing a dehumidifier or a bathroom exhaust fan to dry the air in the restroom. Showering rapidly can be a less expensive solution to prevent humidity buildup.

The purchase of an anti-sweat valve, which raises the temperature of the water in a toilet to prevent condensation, is another option.

2. Cracked toilet

A toilet bowl leaking may have cracks. You’ll notice this when your toilet leaks even when it’s not in use. Have a thorough inspection of the unit to confirm if there is a crack. This might be a tedious task but a vital one.

Applying a superglue to mend the cracks isn’t enough to solve the problem. You might have to call a professional to replace the damaged toilet with a new one.

3. Impaired wax rings

A wax seal connects your toilet to the drain and prevents water from spilling onto the floor. An indication of a faulty wax seal is a wobbly bowl. If left untreated, you’ll have a moderate amount of water leaking from under toilet.

To repair the ring, the toilet must be completely drained before being disassembled. Then, the flange bolts must be changed and a new wax seal with a silicone ring must be installed. The toilet must next be securely fastened to the floor with bolts and caulked.

Read more: Ways to replace a toilet wax ring.

4. Loose bolts

Your toilet’s secure position to the ground is due to the tee bolts. Your toilet will become unsteady and susceptible to swaying when these bolts come loose. Unsecured fasteners could also cause water coming out from bottom of toilet if left unfixed.

To alleviate this problem, you need to have a wrench, pliers, and penetrating oil available. Here’s how to do it:

  • Give the tee bolts a few drops of penetrating oil, then leave them alone for around 15 minutes.
  • Use a pair of pliers to grasp the top of the bolt. Refrain from twisting it in any way. Rather, firmly grasp the pliers’ handle to keep the bolt in place.
  • With the other hand, rotate the bolt.
  • Avoid over tightening. It is advisable to hand-tighten each nut, making a ¼ turn at a time till the toilet is steady.

5. Loose water supply line

Water will continuously trickle at base intermittently from a supply line that is loose. The nuts connecting the water line to the toilet and its valve to the wall should be tight. Otherwise, there will be water on floor around toilet bowl.

If securing the nuts is insufficient, do the following:

  • Spot any obvious gaps on the supply pipe. Use your sense of touch if the gap is not visible.
  • If the pipe has any holes, patch them up using water-resistant tape, ideally plumber’s tape.
  • Otherwise, buy a new supply line and install it. To do this, you must empty the toilet tank and shut off the water connection. Then, remove the old tube and put the new one in place.



How do you fix a toilet that is leaking at the base?

A toilet leaking at the base has different causes, each with its corresponding solutions. Listed in this article are some of the easiest steps you can do to fix a leaking toilet base. If the problem still persists, call a professional plumber.

Is a leaking toilet an emergency?

It depends on the cause and degree of your leaking toilet. If you have a serious leakage that cannot be controlled by a bucket or a towel, call an emergency plumber. A slow water leak in toilet bowl, for instance, is not an emergency.

Why is my toilet leaking when flushed?

Your toilet usually leaks when flushed if its parts have worn out or become too old. Check your flush valves, tank bolts, as well as the flange and wax ring of the toilet. Replace them if you detect any damage.

Why does my toilet leak when taking a shower?

Water coming from the toilet base when shower is on is a clear sign that there is a blockage between your toilet and the sewer.

The obstruction is emphasized when you take a shower, since the buildup of waste in your home’s water lines has a knock-on effect on your shower system.

Why is my brand new toilet leaking from base?

Even when not in use, toilets can still be prone to leaking, as evidenced by the leaking of brand new toilets.

One of the primary suspects for this is that the bolts are loose or the wax ring is not properly placed. Check if both components are put into their respective spots securely. If it’s still leaking, your toilet might have a factory defect.


Now that you know the answer to your query, “Why is my toilet leaking from the bottom” you’ll be able to solve the issue easily. But keep in mind that even though you know how to fix it, it’s always better to prevent toilets from leaking underneath beforehand to save yourself the hassle.

The simplest way to deal with a malfunctioning toilet is to call a licensed plumber, and you might wind up doing that. However, if you don’t mind working alone, the repair could be simple and affordable.

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