Toilet Overflows and Then Drains Completely: A Troubleshooting Guide

D.P. Taylor
Written by D.P. Taylor
Updated May 26, 2022
A white modern bathroom
Photo: PhotoSerg / Adobe Stock

Highlights

  • A toilet that overflows and then drains completely is a sign of clogged rim jet holes

  • Mineral remover will help scrape away the mineral deposits

  • If this doesn't work, it's time to hire a professional for additional troubleshooting

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So you don’t exactly know what to do when your toilet overflows, but you do know that the problem is positively maddening. Wait—now it’s draining toward empty? What gives? Fear not; the solution to an overflowing (and slow draining) toilet may be simpler than you think. Let's dive into why this occurs and what steps you can take to deal with it.

What Are the Causes for a Toilet Overflowing and Then Draining Completely?

Illustration showing the toilet lid, rim, and jet holes

A toilet that overflows and then drains completely is a telltale sign that it's not the big hole on the bottom of your toilet that's the problem, but the little holes around the rim of the toilet you don't see.

These little holes are known as rim jets, and their purpose is to create a swirling motion when you flush the toilet, which helps force the contents of the toilet down the drain.

After a while, sediment can collect along these holes, and it often goes unnoticed because you don't see them. When this happens, the water pressure drops, and you don't get proper water flow or a full flush when you hit the handle. Instead, the water rushes in, fills up the bowl more than it should, and then slowly drains.

What Can I Do to Fix a Toilet That Overflows and Then Drains Completely?

The fix for this problem is simple: just clean the mineral buildup around the rim jet holes. It’s an easy DIY project, too. Keep in mind the following tips as you go.

1. Identify the Mineral Deposits

You can use a small mirror to check underneath the toilet rim for signs of mineral deposits in the rim jet holes. It will usually appear like a scaly buildup that is a lighter color. A darker color would suggest bacteria growth. The buildup will likely be uniform across all holes, but some may be worse than others.

2. Apply Mineral Remover

Mineral remover will usually advertise removing calcium, lime, and rust. Apply the product directly to the deposits and wait a few minutes while the remover works to dissolve the minerals.

3. Chip Away The Deposits

Now is not the time for a light touch—you’ll need elbow grease to clear any buildup the mineral remover loosened. Now, grab a screwdriver or a piece of wire to dislodge it, then follow up with a toilet brush around the bowl as a final clean up.

4. Test the Toilet for Improvement

A close up of finger pushing a flush toilet button
Photo: petzshadow / Adobe Stock

Once you're satisfied with your cleaning job, flush the toilet to see how it performs. If the toilet still overflows then drains completely, but you've noticed some improvement, then you’re on the right track and just need to keep chipping away at the buildup.

When Should I Hire a Pro To Fix a Toilet That Overflows?

After multiple attempts, if the problem persists, it may be time to throw in the DIY towel. Stubborn buildup could be a sign of hard water or a sign that it’s time to replace your toilet

Either way, contact a plumber near you to recommend a course of action rather than wasting hours trying to diagnose your issue. The average cost to repair a toilet is $240. When you've got a toilet issue, it's best to deal with it as soon as possible, so don't delay.

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