Toilet Won't Flush? Common Causes and Easy Fixes
Short answerA toilet that won't flush usually has a clog, a loose or broken chain, too little water in the tank, or blocked rim holes. Lift the tank lid and press the handle. If the flapper does not lift, fix the chain. If the tank is empty, open the valve. If the bowl rises, plunge it.
Safety first
- If the bowl is rising, do not flush again. Reach behind the toilet and turn the shutoff valve clockwise to stop the water.
- Do not pour chemical drain cleaner into a blocked toilet. It can splash back and burn you, and it makes plunging unsafe.
Likely causes
| Cause | How to tell | What fixes it |
|---|---|---|
| Clog in the bowl or drain | The bowl fills high and drains slowly, or not at all. | Use a plunger. If several drains in the house back up, call a plumber. |
| Chain loose, broken or unhooked | The handle feels loose and the flapper does not lift, or lifts and drops right away. | Reattach or replace the chain, leaving about 1/2 inch of slack. |
| Not enough water in the tank | The tank is empty, fills slowly, or the water sits more than 1 inch below the top of the overflow pipe. | Open the shutoff valve fully and raise the level with the fill valve adjustment. |
| Blocked rim and jet holes | The flush is weak, with little water coming in around the bowl, and you see mineral buildup. | Clean the rim holes and jet as described below. |
What you need
- Flange plunger
- Rubber gloves
- Toilet bowl cleaner without bleach or chlorine
- Wire hanger
- Towels
How to fix it
- Stop any overflow first. If the water is near the rim, turn the shutoff valve behind the toilet clockwise until it stops. You can also lift the tank lid and press the flapper closed by hand.
- Look inside the tank. Press the handle and watch. The chain should lift the flapper. If nothing moves, reconnect the chain or replace the handle. If the tank is empty, open the shutoff valve all the way.
- Plunge a clog. Fit the plunger over the bowl opening with water covering the cup. Press down smoothly, then pull up sharply. Repeat several times, then check whether the bowl drains on its own before you flush.
- Set the chain and water level. Leave about 1/2 inch of slack in the chain so the flapper stays open long enough. Raise the tank water to within 1 inch of the top of the overflow pipe, using the fill valve adjustment.
- Clean the rim and jet holes. Shut off the water and drain most of the tank. Pour 1 to 2 cups of toilet bowl cleaner without bleach or chlorine down the flush valve opening and let it sit for several hours or overnight. Scrape the rim holes with a wire hanger, clear the jet hole, turn the water back on and flush several times.
When to call a professional
- Plunging does not clear the clog after two or three tries.
- Sinks or tubs gurgle or back up when you flush, which can mean the problem is in the main drain.
- Sewage is coming up anywhere in the house.
What it costs to have fixed
Toilet Replacement is estimated at $230 to $910 nationally. See your state
Common questions
Why is my toilet not flushing but the handle moves?
The chain has probably come off the handle arm or the flapper. Lift the tank lid, hook the chain back on, and leave about 1/2 inch of slack.
Why won't my toilet flush all the way?
Usually the tank water level is too low, the chain has too much slack, or the rim holes are clogged with minerals. Each of those sends too little water into the bowl.
Why won't my toilet unclog with a plunger?
The plunger may not be sealing, or the clog may be deep in the drain. Use a flange plunger with water covering the cup. If that fails after two or three tries, call a plumber.
Can I use drain cleaner in a toilet?
It is not a good idea. Drain cleaners are caustic, can splash back from a fully blocked drain, and make it dangerous to plunge afterward.
Why is my toilet not flushing strong?
Fluidmaster says minerals such as calcium and lime often build up in the rim feed and jet holes. It also points to a water level more than 1 inch below the top of the overflow pipe, a flapper that closes too soon, or too much slack in the chain. Source
Related repairs
- Burst Pipe in House? What to Do First
- Clogged Drain? How to Unclog a Sink or Tub
- Frozen Pipes? How to Thaw Them Safely
- Garbage Disposal Not Working? Reset and Unjam It
- Leaky Faucet? How to Fix a Dripping Faucet
- Low Water Pressure in House? How to Find the Cause
- No Hot Water in House? What to Check First
- Sewer Smell in House? Causes and What to Do
Last verified 2026-11-01
Sources
- Fluidmaster: How to Fix a Weak or Incomplete Toilet Flush — Clogged rim and jet holes, water level within 1 inch of the overflow pipe, 1/2 inch of chain slack, and the cleaning method
- Kohler: Toilet Troubleshooting — Checking the trip lever chain and water level for a poor flush
- University of Florida IFAS Extension: Making Simple Repairs, Clogged Drains — Plunger technique of pressing smoothly and pulling sharply; chemical drain cleaner cautions, including that you should not plunge after using one
- Poison Control: What's in Drain Cleaner — Drain cleaner burns and splashback from fully blocked drains
General information, not professional advice. Conditions, codes and prices vary. Turn off power, gas or water before any work, and hire a licensed professional when in doubt. Cost figures are our estimates, not quotes.