Why Does My Toilet Keep Clogging? 7 Causes and Fixes
One clogged toilet is an annoyance. A toilet that clogs every week is a sign that something else is going on, either in the toilet itself or further down the drain line.
Quick answer: A toilet usually keeps clogging because of too much paper or non-flushable items, a partial clog left in the trap, mineral buildup in the toilet's jets, an older low-flow toilet, a blocked vent, or a problem in the main sewer line. If other drains back up or gurgle when you flush, the problem is likely the sewer line, not the toilet.
7 Reasons Your Toilet Keeps Clogging
1. Too Much Toilet Paper or Non-Flushable Items
Toilets are designed for human waste and toilet paper, in reasonable amounts. Large wads of paper, wipes (even ones labeled "flushable"), paper towels, cotton swabs and feminine products are the most common cause of repeat clogs. Try flushing midway for heavy use, and keep a trash can in the bathroom.
2. A Partial Clog Left in the Trap
Plunging can push water past a blockage without removing it. A toothbrush, toy or wad of wipes lodged in the toilet's built-in trap lets water through slowly but catches everything that comes after it. A toilet auger (closet auger) can usually pull it out. If it can't, the toilet may need to be removed to clear it.
3. Mineral Buildup in the Rim and Siphon Jets
Northern Nevada's hard water leaves mineral scale in the small rim holes and the siphon jet at the bottom of the bowl. As those openings narrow, the flush gets weaker and waste doesn't clear completely. Cleaning the rim holes and jet can restore a stronger flush.
4. An Older Low-Flow Toilet
Some early low-flow toilets don't have enough flushing power to clear the bowl and trapway. Modern high-efficiency toilets use the same small amount of water much more effectively, so replacing an older model often ends the problem.
5. A Tank Problem That Weakens the Flush
If the water level in the tank is too low, or the flapper closes too early, the toilet doesn't get a full flush. The same parts cause a toilet that won't stop running. See our running toilet repair guide.
6. A Blocked Plumbing Vent
Vent pipes let air into the drain system so wastewater flows freely. If a vent on the roof is blocked by leaves, debris or a bird's nest, the toilet drains slowly, clogs easily and often gurgles. Here's more on why a toilet bubbles or gurgles.
7. A Problem in the Main Sewer Line
When the clog is in the main line, the toilet is often the first fixture to show it because it sends the most water at once. Tree roots, grease buildup, a sagging pipe or a collapsed section can all cause it. Signs include several drains backing up at once, water coming up in the tub when you flush, and gurgling in other fixtures. Learn the sewer line distress signs. If your home is on septic, a full tank can cause the same symptoms. See the signs of septic tank problems.
How to Fix a Toilet That Keeps Clogging
- Use the right plunger. A flange plunger seals into the toilet drain much better than a flat sink plunger.
- Try a toilet auger. If plunging doesn't clear it, or the toilet clogs again within days, a closet auger can reach and pull out what's stuck in the trap.
- Skip chemical drain cleaners. They rarely clear toilet clogs, they can damage pipes and seals, and they make the job dangerous for whoever clears the clog next.
- Check the tank. Make sure the water level reaches the fill line and the flapper stays open long enough for a full flush.
- Clean the rim holes and siphon jet if you see mineral buildup.
- Call a plumber if other drains are affected, you hear gurgling elsewhere, or the toilet keeps clogging after you've tried these steps.
When to Call a Professional
A plumber can auger the toilet, check the vent and, if needed, run a sewer camera inspection to see whether the main line has roots, buildup or damage. Main line clogs are cleared with professional drain cleaning or, for grease and roots, hydro jetting. If sewage is backing up into your home, treat it as an emergency and call for 24/7 emergency plumbing.
Frequently Asked Questions
Why does my toilet clog every time I flush?
Usually something is stuck in the trap, the flush is too weak because of a tank or mineral buildup problem, or there's a partial blockage further down the line. If plunging only helps for a day or two, use a toilet auger or call a plumber.
How do I know if it's the toilet or the main sewer line?
If only the toilet clogs, the problem is usually in the toilet or its drain. If the tub, shower or floor drains back up or gurgle when you flush, the main sewer line is the likely cause.
Are "flushable" wipes safe for toilets?
Not really. Many don't break down quickly and can snag in the trap or build up in the sewer line or septic tank. It's safest to put them in the trash.
Need Help With a Toilet That Keeps Clogging?
Easy Rooter Plumbing has cleared toilets, drains and sewer lines in Reno, Sparks and Northern Nevada since 1979. We'll find out why the clog keeps coming back and fix the cause, not just the symptom. Call (775) 331-3636.