Top 5 Reasons Why Toilets Clog

Plunger working on Toilet Clog
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Your toilet is one of the most commonly used fixtures in your home. Which 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: away from your toilet. Keep an eye out for these five toilet-clogging culprits.

1. You Have a First-Generation Low Flow Toilet

Many older low flow toilets lack the necessary pressure to clear their trap and drain, resulting in regular clogs.

Look at the back of your toilet for a stamped date. If your toilet was made in the mid-1990s, you could have a first-gen low flow toilet. If this is the case, don’t feel the need to rush into a replacement. You can reduce clogs in low flow toilets by limiting toilet paper use and avoiding clog-prone items.

2. You Flushed Non-Flushable Items

Your toilet is designed to only dispose of certain materials. Flushing items like Q-Tips, cotton balls, wet wipes and floss can restrict drainage and cause constant backups. 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 hard-to-flush items easier.   

3. You Have a Clogged Trap

Your trap is a curved pipe that sits below your toilet and keeps sewer gasses from entering your home.

Toilet paper, paper towels and a variety of non-flushable items can clog your trap and cause a backed-up toilet. A few minutes with a plunger should loosen any blockage and remove the clog. Limiting toilet paper use and keeping difficult-to-flush items out of your toilet should keep your traps clear.

4. The Plumbing Vent Is Blocked

Modern toilets use roof vents to funnel fresh air into your plumbing system and boost flushing pressure. Over time, these vents can become clogged with leaves, sticks and animal nests. A blocked toilet vent will reduce your flushing pressure and cause regular clogs. It’s best to hire a pro to clear your vents. Blockage can be hard to spot and will require special tools to remove.

5. There's an Issue With the Sewer Line

Regular clogs in multiple toilets—and drains—are usually the sign of a sewer line problem. Clogs are normally caused by a buildup of waste material, toilet paper and non-flushable items. 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.​