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Why Does My Toilet Keep Clogging: 5 Possible Reasons

man snaking a toilet

Dubbed the worst toilet disaster in history, on July 26, 1184, the King of Germany, Henry VI, dozens of nobles, and courtiers drowned in a latrine system when the citadel they were holding court proceedings on collapsed. Historians place the number of those killed by the inability to swim from raw human excrements at between 60 and 100 people!

While it is almost impossible for such horrifying history to repeat itself, nowadays, people must deal with many toilet issues, including clogging. Clogging happens when you least expect it and, in unfortunate cases, when there is company! Knowing why your toilet keeps clogging up will help you resolve the issue. Here are some causes and the possible solution you should follow.

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The 5 Reasons Your Toilet Keeps Clogging

1. Old House With an Outdated Low-Flow Toilet System

plumber working with toilet leak
Image Credit: New Africa, Shutterstock

Typically, an old flush toilet uses 3.5 to 7 gallons of water per flush. In a bid to save water, the federal government passed the Energy Policy Act that restricted a toilet flush to 1.6 gallons in 1992. The law came into effect on January 1, 1994.

If you are one of the Baby Boomers still enjoying the glorious days of living in a house that was built before that time, chances are you have a low-flow toilet. Even though these toilets had to comply with the new law, working with less water was a bad option. Reduced water tank resulted in low pressure, which could not satisfactorily push the waste down the drain, causing clogging.

To resolve this, you may need to call the plumber to redesign the drainage and increase the water flow gradient to a steep slope. Though the flush water will be low pressure, having gravity on your side will carry away most waste to fix the clogging issue.

Alternatively, replace the toilet with modern dual flush or pressure-assisted flush toilets. The dual flush works with different water volumes. Solid waste flushes with 1.28–1.6 gallons of water, while liquid wastes consume half of that. Together with compressed air, the system clears most of the waste from the piping.

2. Foreign Objects Clogged in the Toilet Trap

The toilet trap is the pipe connecting the bowl to the plumbing. It is usually either an S-shape or P-shape pipe whose purpose is to prevent sewer gasses from leaking back into the bathroom. The trap also prevents foreign objects that are not supposed to go down the main sewer line from flowing through. It basically prevents solid objects from clogging the toilet.

Continuous release of non-flushable items such as feminine hygiene products, diapers, baby wipes, paper towels, hair, and gum block the trap system. You can know this when there is a foul rotten egg-like odor in the house, the water flow after flushing is weak, or the drain is not clearing up quickly.

Use a plunger to carefully apply pressure to the toilet trap by pumping it in and out in push-pull action. Plunge 5–10 times and release the plunger. The clog should be out by then. If not, use a toilet auger, and if this also cannot unclog the toilet, a plumber will.

3. Blocked Plumbing Vent

A plumbing vent removes sewer gasses and lets in air to increase pressure in the pipes. When the plumbing vent is blocked, the toilet clogs up.

The lack of airflow creates a semi-vacuum in the drainage that slows down the flow of wastes instead of settling down. To fix this, first, recruit someone to help you test if there is a problem with the vent.

Second, climb up the vent and cover it with your hands and let the other person flush the toilet. If there is no suction pressure acting on the hands, the pipe is blocked. Take a 10–20 ft long plumber’s snake or auger and push it down through the drainage bit by bit to the barrier. Keep pushing the auger until you go through the obstruction, then start pulling it back. The auger will unblock the pipe.

Cover the vent again with your hand and have someone inside flush the toilet. The toilet will be unblocked if you feel suction.

To keep the vent clear, trim tree branches hanging over it to prevent leaves from accumulating down there. Also, cover the vent with a vent cap to keep away small animals.

4. Hard Water Salt Buildup

Hard water has a high concentration of dissolved minerals. These include calcium, chlorides, sulfates, and magnesium salts. When flushed down the toilet, the minerals leave a residue that builds up like a stalagmite in a limestone pillar. The result is a restricted pipe and severe blockages.

Pour distilled white vinegar or lemon juice into the toilet bowl and let it sit overnight to dissolve the compounds. Scrub off the surface using a thistle brush the next day.

Investing in a water-softening system, which replaces calcium and magnesium ions with sodium ions, is a permanent solution.

5. Sewer Line Problems

Plumber snaking
Plumber snaking (Image Credit: Walter Siegmund, Wikimedia CC BY-SA 3.0)

Sewer line blockages are one of the toughest to resolve because there are several reasons leading up to this, and some of them may be caused by your neighbors.

It could be caused by:
  • Debris that keeps building up from the drain lines
  • Years of the buildup of grease from the sink
  • Overgrown tree roots that penetrate the sewer line
  • Foreign objects

If you suspect the sewer line is the problem, of course, after ensuring your toilet system is fine, call a licensed plumber or authorities. They will do a camera inspection of the sewer line and find out where the source of the clog is. The inspection involves a small waterproof camera that is mounted on a flexible cable. Authorities will push it through the sewer line, and as they review the footage, blockages will be clearly visible.

Sewer blockages are a community affair and require collective responsibility to prevent them from happening. How do you prevent it?

Educate your neighbors on the following tips:
  • Don’t pour grease or its derivatives such as butter, salad dressings, fatty meat trimmings, and creamy sauces down the sink.
  • Put a hair catcher in the shower drain to prevent hairs from lodging into the sewer pipe.
  • If there are trees or deeply rooted bushy plants growing near the sewer line, flush ½ a cup of copper sulfate down the toilet to kill new root growth every 10 weeks or so. The sulfate only acts on the roots and spares the entire plant.
  • Lastly, call a plumber every 18 months to clean the pipes. They will use a hydro jet that powerfully blasts out built-up grime in the sewer system.

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Clogged toilets are either a result of negligence or unavoidable circumstances. It’s inevitable if you continuously let grease, hair, and unwanted solids flow through the toilet. In contrast, let authorities know the sewer system is blocked if you suspect so.

Either way, prevent your toilet from blocking through routine inspections, using a water softener, and preventing non-flushable items from flowing through. Also, it will not cost a lot to be a plumber’s friend!

Featured Image Credit: David Spates, Shutterstock


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