5 Reasons Why Toilets Get Clogged

Plunger working on Toilet Clog
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Your toilet is one of the most commonly used fixtures in your home. This means that a clogged commode can lead to a frustrated family—and very unpleasant cleanup. Understanding why your toilet backs up will help you prevent future blockage, and keep your plunger where it belongs—stored away because you never need it. Keep an eye out for these five toilet-clogging culprits.

1. You Have a First-Generation, Low-Flow Toilet

Modern toilets use a variety of low-flow designs aimed at saving water. The early forms of these toilets may lack the necessary pressure to clear the internal trap and drain, meaning that they often develop clogs. Look at the back of your toilet for a stamped date. If your toilet was made in the mid-1990s, you could have one of these first-generation low-flow toilets. If this is the case, don’t feel the need to rush into a replacement. You can sometimes reduce clogs in low-sflow toilets by limiting toilet paper use and avoiding clog-prone items. But if these efforts don't help, the solution will be to install a more up-to-date toilet.

2. Someone Tried to Flush Non-Flushable Items

Your toilet is designed to only dispose of certain materials. Toilet tissue, for example, is designed to quickly dissolve in water, so it rarely causes a problem. But disposable tissues (Kleenex) or paper towels are not meant to be flushed down a toilet. Flushing other items, such as Q-Tips, cotton balls, wet wipes, and dental floss can restrict drainage and cause constant backups in the toilet. Speak with your family members about what’s safe to flush and what isn’t. If you have younger children, keep a list of non-flushable items close to your toilet. It’s also a good idea to keep a large trash can in your bathroom. This will make disposing of non-flushable items easier.  

3. The Toilet Trap Is Blocked

Your trap is a curved segment of the porcelain fixture that is built into the lower bowl unit of your toilet. It is designed to hold standing water and keep sewer gases from entering your home. Toilet paper, paper towels and a variety of non-flushable items can clog the trap and cause a backed-up toilet. More than one toilet has become clogged when a pocket comb became lodged in the internal trap. A few minutes with a plunger should loosen any blockage and remove the clog. More stubborn clogs can be cleared with a toilet auger. Limiting toilet paper use and keeping non-flushable items out of your toilet should keep the toilet trap clear.

4. The Plumbing Vent Is Blocked

Modern toilets, as well as other plumbing fixtures, use roof vents to funnel fresh air into the plumbing system and prevent air-pressure vacuums that can hinder drain flow. Over time, these vents can become clogged with leaves, sticks, and animal nests. A blocked toilet vent will reduce the drain flow and can cause regular clogs. It’s best to hire a pro to clear your vents, since blockage can be hard to spot and will require special tools to remove.

5. There Are Main Sewer Line Problems

Regular clogs in multiple toilets and drains are usually signs of larger sewer line problems. Clogs in multiple fixtures are normally caused by a buildup of waste material, toilet paper, and non-flushable items in the main drain and sewer lines. Tree roots can also puncture your sewer line, letting in sediment and other blockage-causing debris. Sewer line problems can cause major problems inside and outside of your home, and even threaten the health of your family. It’s best to hire a pro to tackle any sewer-related issues.​