Hidden Cause of a Toilet Leak

Toilet leak problems are one of the most common plumbing calls we receive. A toilet leak shouldn’t be ignored because it can damage your bathroom floor and waste water. There are a few reasons a Willimantic CT toilet can leak but I’m just going to cover one in this blog.

Toilet tank 101

Before I go any further, let’s back up and go over some basics. Most people are familiar with the parts inside the toilet tank, such as the flapper and the chain. However, you should also know about the parts that connect your toilet tank to the bowl itself. made a great graphic that clearly shows the parts and the names of each piece:


[Image Credit:]

The parts that you need to take note of are the Washer, Nut, Tank Bolt, and Rubber Washer. Each piece is either made of metal or rubber. These parts are important because they are meant to securely hold your toilet together. When you lift the cover to your toilet tank and look down, you will be able to see the top of the Tank Bolt. If you look under your toilet bowl, you will find the bottom of the Tank Bolt along with the Washer and Nut.

Cause of toilet leak

Your toilet tank is pretty much a bucket of water. If there’s a hole or a crack in the bottom of a bucket, what happens? The water will leak out, right? Same thing with your toilet tank. An improper installation of any of the parts above can cause a leak. For example, if a washer is left out, a tight seal won’t be made and water will find its way through, leaking along the bowl and onto your floor.

Over time, water can and will corrode the metal and rubber of each piece. If the rubber on the Washer corrodes, it will eventually dissolve and that will leave a space for water to pass by. If the top of the Tank Bolt corrodes, water will leak AND your toilet tank could topple over!

Show & tell

Below are pictures that one of our plumber technicians took at a Willimantic CT toilet leak. Our customer thought that the wax ring of her toilet needed to be replaced because she saw water on the floor, around the bottom of the toilet.

Our plumber technician removed the toilet tank cover to take a peak. He saw this:


See that green circle? That was laying in the bottom of the toilet tank. It SHOULD be on top of the Tank Bolt…and it should NOT be green! The green is corrosion. The water ate away at the metal until it eventually broke off. Since that circle helped create the seal from the toilet tank to the bowl, its absence allowed water to seep through. That’s not all! He also discovered this:


Yeah, yeah, the top of the Tank Bolt is green and it’s broken off – you’ve already told us that! That’s what you’re thinking, right? I’m glad you caught that part, but what ELSE is missing from this part? Compare it to the picture above.

Not only is the Tank Bolt corroded and broken, the Rubber Washer is missing completely! The acidity of the water completely deteriorated the rubber, also playing a part in causing the toilet leak.

Your Willimantic CT plumber

Our plumber technician replaced all the corroded parts after explaining the cause of the toilet leak to our customer. The wax ring didn’t need to be replaced at all. Once the repair was completed, the toilet didn’t leak anymore. Our customer prevented water damage to her floor and our repair was done the same day.

We recommend taking a peak under your toilet tank cover periodically to avoid a future toilet leak. If you notice signs of corrosion, such as sediment in the bottom of the toilet tank, give our office a call to schedule a repair: 860-228-1036.

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