Toilet keeps clogging

Find out whether it’s the flush, the paper or something stuck, and fix that.

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Quick answer

A toilet that clogs often has a weak flush or a partial blockage. Weak swirl? Clean the rim holes and check the water level. Strong flush that still clogs? Something is stuck: run a toilet auger.

For a repeat clog: RIDGID K-6DH auger$89.34 at AmazonPrice as of Oct 23, 2026, 5:30 AM EDT

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What to try first

1. 1
   Fill a jar

   Put tap water in a quart mason jar.

2. 2
   Add one sheet

   Drop in a single-ply sheet of the toilet paper you use.

3. 3
   Shake 10 seconds

   Shake moderately for about 10 seconds, the length of a typical flush.

4. 4
   Compare

   The paper that dissolves or shreds most will flush best and clog least, Kohler says.

Kohler explains why paper matters: some grades contain lanolins, dyes and other compounds that add softness, fragrance or strength but keep the paper from breaking down in flowing water. Paper makers also use different pulp, so two rolls that feel alike can behave very differently in a toilet.

Try two or three brands side by side in jars. If yours stays in a sheet while another shreds, switching paper is the easiest fix on this page. Wipes, even ones sold as flushable, are worth keeping out of a toilet that already clogs often.

1. 1
   Shut off and drain the tank

   Turn off the supply valve and hold the flapper open to let most of the water out.

2. 2
   Pour in a lime cleaner

   Fluidmaster pours 1–2 cups of a toilet bowl cleaner such as Lime-A-Way down the flush valve opening, holding the flapper open. Don’t let it spill into the tank.

3. 3
   Let it sit

   Leave it several hours or overnight; Kohler says 8–24 hours. It works into the channels and dissolves the buildup.

4. 4
   Ream the rim holes

   Work a wire hanger, paper clip or finishing nail in and out of the holes under the rim to break up hard deposits.

5. 5
   Clear the jet

   Bend a small hook in a wire hanger and fish out any paper or waste trapped in the jet hole at the bottom of the bowl.

6. 6
   Refill and flush

   Turn the water back on and flush several times to clear the cleaner and loosened deposits.

Kohler adds a detail for stubborn rim holes: block them with wet paper towels held by plumber’s putty so the cleaner stays in the rim channel. Kohler also notes that bits of vitreous china can shake loose during shipping and lodge in a new toilet’s rim holes, one reason a brand-new toilet can flush weakly.

Next, check the water level. Fluidmaster says that if the water is more than 1 in. below the top of the overflow pipe, there may not be enough for a good flush. Raise it to within 1 in. of the top with the adjustment screw on the fill valve, or by raising the fill valve.

Fluidmaster warns against in-tank drop-in cleaners containing bleach or chlorine: they damage tank parts, may cause flooding and void its warranty.

If the water level is right and the flush is still short, the flapper may be dropping before enough water leaves the tank. Fluidmaster says most toilets need only about 1/2 in. of slack in the flapper chain; too much and the flapper doesn’t lift far enough.

On toilets that use 1.6 or 1.28 gallons per flush, Fluidmaster’s adjustable flappers let you set how long the flapper stays open. The Fluidmaster 502P21 fits most 2 in. flush valve toilets from 1.28 to 3.5 gallons per flush, per its listing, and carries a five-year warranty. Toilets that use 5.0 gallons or more should use a non-adjustable flapper, Fluidmaster says.

1. 1
   Read the setting

   The number in front of the chain on top of the flapper is the current setting, from 1 (closes fastest) to 9 (stays open longest).

2. 2
   Test with paper

   Drop 2–3 pieces of toilet paper in the bowl and flush.

3. 3
   Step down

   If the bowl clears, lower the setting by one and flush again.

4. 4
   Set it

   When the bowl stops clearing, go back up one setting. That’s the most water-efficient setting that still clears.

For a toilet that keeps clogging, I’d set it one notch higher than that, trading a little water for a margin on heavy flushes. For a 3 in. flush valve, Fluidmaster points to its 3 in. flush valve kits instead of the 2 in. 502.

Setting the tank water level

1. 1
   Find the mark

   Look for the water line marked inside the tank, or measure down from the top of the overflow pipe.

2. 2
   Compare

   Fluidmaster’s rule: the water should sit within 1 in. of the top of the overflow pipe.

3. 3
   Adjust the fill valve

   Turn the adjustment screw or clip on the fill valve to raise the float, or raise the whole fill valve on its shank.

4. 4
   Flush and recheck

   Let it refill and check again. Water should never run into the overflow pipe; if it does, lower it slightly.

EPA is candid about the history. It says the low-flow toilets of the 1990s were sometimes linked to performance problems, such as needing a double flush, and that makers have since redesigned them. When EPA wrote the WaterSense criteria it added a test of how well a toilet clears waste from the bowl, and those performance criteria have since been adopted into the national plumbing standard, ASME A112.19.2/CSA B45.1.

So a modern 1.28 or 1.6 gallon toilet that clogs every week isn’t doing what it was tested to do. Before blaming the low flow, run through the paper, rim, water level and flapper checks; one of them usually brings the flush back.

EPA describes the reduced flush on a dual-flush toilet as a smaller volume of water for liquid waste. Using the reduced button for solids is a common cause of clogs on these toilets. Use the full flush for paper and solids.

Many dual-flush toilets use a canister or tower flush valve instead of a flapper, so the flapper steps above don’t apply. Fluidmaster has separate guidance for dual flush toilets that don’t work properly, and Kohler’s support guide branches by canister and flapper valves for the same reason.

EPA says household leaks can waste 180 gallons a week, toilets are often the culprit, and most toilet leaks come from old or worn-out flappers. A flapper that leaks lets the tank drop between flushes, which means a lower water level and a weaker flush when you need it.

If you hear the tank refill on its own, or the water level in the tank creeps down, replace the flapper. EPA calls it an inexpensive part that’s quick and easy to replace.

The bowl’s standing water is part of the flush: it helps start the siphon that pulls waste through the trap. Kohler says that if the bowl water level is low, check that the rim feed hose is connected to the flush valve.

The rim feed hose, often called the refill tube, runs from the fill valve and directs water into the bowl while the tank refills. Kohler says it goes into the top of the flush valve, also called the overflow tube, sometimes held with a clip, and should not point out into the tank. If it’s loose, the tank refills but the bowl stays low, and the next flush is weaker.

A tank that doesn’t refill to its line gives a short flush next time. Fluidmaster says the main reason is the fill valve: debris in the valve, supply line or shutoff restricts the flow, and valves in use 7 years or more start to wear out.

1. 1
   Shut off and flush

   Turn off the supply and flush the tank empty.

2. 2
   Lift the float cup

   Hold the float cup and the shaft all the way up so the valve doesn’t turn.

3. 3
   Remove the cap

   On Fluidmaster’s 400A, turn the cap and arm counterclockwise 1/8 turn and lift it off.

4. 4
   Flush the inlet

   Hold a cup upside down over the opening and turn the water on full for 10–15 seconds to blow out debris.

5. 5
   Reassemble or replace

   Lock the cap back on. If it still fills slowly, Fluidmaster’s next step is a new seal or a new fill valve.

If a strong flush still clogs every few days, the usual story is a partial blockage in the trapway: a comb, a toy, a pen cap or a wad of wipes that lets water pass but catches paper. Plunging pushes the paper through each time, and the object stays put.

RIDGID says 3 ft of auger cable reaches completely through the toilet, and its 6 ft K-6DH can clear beyond it. The RIDGID K-6DH cranks by hand or with a battery drill under 500 rpm, has a drop head for toilets where the outlet sits low, and carries RIDGID’s full lifetime warranty.

1. 1
   Protect the bowl

   Seat the auger’s bend in the bowl outlet so the cable, not the metal tube, touches the porcelain.

2. 2
   Feed and crank

   Push the cable in while cranking clockwise until you feel it catch or pass through.

3. 3
   Pull back slowly

   Keep cranking as you retract. Hooked objects come back with the cable.

4. 4
   Flush with paper

   Drop a few sheets in and flush. If it clears cleanly, the trap is open.

5. 5
   Pull the toilet if needed

   A hard object that won’t pass or hook may need the toilet lifted and pushed out from below.

The toilet auger guide compares drop-head, bulb-head and short augers, and toilet auger vs drain snake explains why a regular drain snake isn’t the right tool for a toilet.

A flat sink plunger won’t seal on a toilet’s outlet. A flange or beehive plunger does. The Korky BeehiveMAX 97-5A has a beehive head with a 6 in. cup and a 16 in. collapsible T-handle, and Korky says it fits all toilet makers, including high-efficiency bowls.

Seat the plunger, push gently first to push out the air, then work it with firm strokes while keeping the seal. Enough water in the bowl to cover the cup makes the stroke move water instead of air. The toilet plunger guide compares flange and beehive heads.

The codes require every trap to be protected from siphonage and back pressure by venting. A blocked vent starves the drain of air, so water slows and the toilet’s flush loses its pull. Vents usually run through the roof, so clearing one is a plumber’s job.

The IPC sets every fixture trap’s water seal at 2 to 4 in. deep. A toilet is unusual in the code: it’s treated as self-siphoning, and the IPC doesn’t limit how far its trap can sit from the vent fitting. That’s why a toilet tolerates odd vent layouts better than a sink, and why gurgling at a toilet usually means a real blockage downstream.

A main line clog shows up first at the lowest fixture. The clogged drain vs main line guide explains how to tell, and why the main drain keeps clogging covers the line itself.

Best for something stuck in the trap

RIDGID K-6DH

$89.34 at Amazon

Check it on Amazon

Price as of Oct 23, 2026, 5:30 AM EDT

Best for an everyday clog

Korky BeehiveMAX

$31.53 at Amazon

Check it on Amazon

Price as of Oct 23, 2026, 5:30 AM EDT

Best for a weak, short flush

Fluidmaster 502P21

$6.48 at Amazon

Check it on Amazon

Price as of Oct 23, 2026, 5:30 AM EDT

Best for a slow-filling tank

Fluidmaster K-400H-039

$16.97 at Amazon

Check it on Amazon

Price as of Oct 23, 2026, 5:30 AM EDT

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.

I’ve used each of these. If I could keep only one, it would be the auger: it’s the only tool here that removes what causes a repeat clog instead of pushing the latest one through.

Sources

• Kohler Assist, “Frequent Toilet Clogging” and “Correct Poor Toilet Rim Wash” (assist.kohler.com).
• Fluidmaster, “How to Fix a Weak or Incomplete Toilet Flush” (fluidmaster.com).
• RIDGID K-6DH (59802) toilet auger documents, as checked for this site’s toilet auger guide.
• Korky BeehiveMAX 97-5A documents, as checked for this site’s toilet plunger guide.
• International Code Council, IRC P3201.3 (trap seals protected by venting).
• US EPA WaterSense, Residential Toilets page (epa.gov/watersense).
• Code of Federal Regulations, 10 CFR 430.32, water closet maximum flush rates.
• Product listing details for the four items (Amazon Creators API, Oct 23, 2026).