How to Fix a Toilet That Won’t Flush
A toilet that won’t flush is annoying, but you can usually fix it yourself. Most problems are simple: a clog, a loose chain, or low water in the tank. This guide will walk you through the common causes and easy fixes.
Pro Tip: Before you start, turn off the exhaust fan and listen. The sounds you hear (or don’t hear) when you flush can tell you a lot about what’s wrong.
Safety First
Toilets are not dangerous, but you should still be careful.
- Do not use harsh chemicals if you can avoid them. They can burn your skin and damage pipes.
- If you must use a chemical cleaner, wear gloves and eye protection.
- If water is leaking onto the floor, shut off the water to the toilet before working.
Tools You May Need
- Plunger (flange or toilet plunger, not a sink plunger)
- Rubber gloves
- Bucket or small container
- Sponge or old rags
- Adjustable wrench
- Flathead screwdriver
- Wire coat hanger or small drain snake (for light clogs)
- Utility knife or scissors (for cutting chain or flapper if needed)
You might not need all of these, but it is good to have them ready.
Step 1: Check for a Simple Clog in the Bowl
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Look into the bowl and see if the water is very high or rising slowly.
If the water level is high and not going down, you likely have a clog. -
Do not keep flushing.
More flushing can make the toilet overflow and create a mess. -
Use a good toilet plunger.
A flange plunger has a rubber “lip” that fits into the toilet hole better than a flat plunger. -
Place the plunger over the drain hole at the bottom of the bowl.
Make sure the rubber part is fully under water for a good seal. Add water if needed. -
Push down slowly, then pull up sharply 10–15 times.
Start gently so you don’t splash, then increase force as the seal improves. -
Flush once to test.
If the water goes down quickly and refills, the clog is gone. If not, repeat plunging.
Step 2: Check the Tank Parts (Handle, Chain, Flapper)
If the bowl is not clogged but the toilet still will not flush, the problem is likely in the tank.
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Remove the tank lid carefully and set it on a towel so it won’t crack.
The tank is the back part that holds water. -
Flush the toilet while watching the inside of the tank.
See what moves and what does not. This will help you find the problem. -
Check the handle and lever.
When you press the handle, an arm (called a lever) inside the tank should move up.- If it feels loose or floppy, the nut inside may be loose.
- If nothing moves, the handle or lever may be broken.
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To tighten: use a wrench to gently tighten the nut on the inside where the handle meets the lever.
Turn it snug, but do not over-tighten or you can crack the tank. -
Check the chain that runs from the lever to the rubber flapper at the bottom.
- If the chain is disconnected, re-hook the chain to the small hole in the lever.
- If the chain is too loose, move the clip up the chain so it pulls the flapper up farther.
- If the chain is too tight, the flapper may not seal. Move the clip down the chain to add a little slack.
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Check the flapper (the rubber piece that covers the hole at the bottom of the tank).
- Lift the flapper by hand and see if water rushes into the bowl.
- If the toilet flushes when you lift it, the flapper or chain was your problem.
Step 3: Adjust or Replace the Flapper
If the flapper is old, warped, or not sealing, the toilet may not flush well.
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Turn off the water supply to the toilet.
The shutoff valve is usually on the wall behind or beside the toilet. Turn it clockwise. -
Flush the toilet and hold the handle down to empty most of the water from the tank.
Use a sponge or rag to remove any extra water if needed. -
Inspect the flapper closely.
If it is cracked, stiff, or does not sit flat on the opening, it needs to be replaced. -
Unhook the flapper from the ears on the overflow tube (the vertical pipe) and unclip the chain.
Note how it was attached so you can install the new one the same way. -
Install the new flapper by clipping its side tabs onto the overflow tube and hooking the chain to the lever.
Leave just a little slack in the chain, about 1/4 inch. -
Turn the water back on and let the tank fill.
Then test flush to make sure the flapper lifts fully and closes firmly.
Step 4: Make Sure the Tank Fills High Enough
If your tank does not fill with enough water, the flush will be weak or not work at all.
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Look inside the tank for a water level mark or line.
If there is no mark, the water should normally be about 1 inch below the top of the overflow tube. -
Check the float (this controls water level). You may have:
- A float ball on the end of a rod, or
- A vertical “float cup” on the fill valve.
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For a float ball: gently bend the metal rod down to raise the water level, or up to lower it.
Do small adjustments, then let the tank refill and check the level. -
For a float cup: turn the adjustment screw or slide the clip on the side of the fill valve.
This will raise or lower the float and change the tank water level. -
Flush and test after each adjustment.
When the water is at the right height, your flush should be stronger.
Step 5: Fix a Weak or “Half” Flush
If the toilet flushes but not strongly, clean and adjust a few parts.
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Check that the flapper stays up long enough.
If it drops too fast, shorten the chain slightly so it opens higher. -
Make sure the tank water is not too low.
Follow the steps above to adjust the float. -
Clean the rim holes under the toilet bowl rim.
Mineral build-up can block water flow. -
Use a small mirror and a stiff brush or wire to scrub the tiny holes under the rim.
Wear gloves and go slowly so you do not chip the porcelain. -
Flush and see if the water flows stronger around the bowl.
A better flow means a better flush.
Step 6: Check the Fill Valve (If Tank Won’t Refill)
If the tank does not refill, or fills very slowly, your fill valve may be clogged or failing.
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Turn off the water supply to the toilet.
Flush to empty most of the water from the tank. -
Remove the top cap of the fill valve (follow the instructions on the valve, if printed).
Some caps twist off; others have a clip. -
Look for dirt, sand, or debris inside the valve.
Use a rag to gently wipe it out. -
Briefly turn the water supply on (with the cap off) to flush out any leftover debris.
Aim the flow down into the tank and be ready to turn it off quickly. -
Reassemble the valve cap and turn the water back on.
Let the tank fill and test flush. -
If the valve still does not work right or is very old, replace the fill valve with a new one.
Most replacement kits come with clear instructions and only need basic tools.
Step 7: When to Call a Plumber
Sometimes the toilet problem is bigger than normal DIY work.
- If you plunged many times and the clog keeps coming back, the main drain line may be blocked.
- If water leaks from the base of the toilet, the wax ring may have failed.
- If you see cracks in the bowl or tank, the toilet itself may need to be replaced.
- If you smell strong sewer gas or hear gurgling in other drains, you may have a vent or main line issue.
In these cases, stop using the toilet and call a licensed plumber. It can save you from bigger repairs later.
Final Check
After each fix, always:
- Flush the toilet several times.
- Watch the tank and bowl to be sure everything moves smoothly.
- Check the floor around the toilet for leaks.
If the toilet flushes strongly, refills on its own, and nothing leaks, you’ve done the job right.
