How to Fix a Toilet That Won't Flush

Most toilet flush problems stem from issues with the flapper, chain, or water level in the tank. Check these components first before moving to more complex repairs.

  1. Check Your Water Level First. Carefully lift off the tank lid and set it aside on a towel. Look at the water level inside the tank. It should reach about one inch below the rim of the tank or to the water line marked on the tank wall. If the water level is too low, your toilet won't have enough force to flush properly.
  2. Spot Flapper Damage Fast. The rubber flapper should sit flat against the valve seat at the bottom of the tank. If it's warped, cracked, or has mineral buildup preventing a good seal, water will continuously leak from the tank into the bowl. Clean around the flapper seat and replace the flapper if it's damaged or won't seal properly.
  3. Fix Chain Slack Issues. The chain should have slight slack when the flapper is closed, but not so much that it gets caught under the flapper. If the chain is too long, it won't lift the flapper high enough. If it's too short, it will prevent the flapper from sealing. Adjust the chain length by moving it to a different hole in the flush arm or flapper.
  4. Balance Water Level Right. If your toilet has a ball float, bend the arm downward to lower the water level or upward to raise it. For newer toilets with a fill valve, there's usually an adjustment screw on top. Turn it clockwise to lower water level, counterclockwise to raise it. The goal is to have water stop filling when it reaches the proper level.
  5. Unclog With Purpose. If water drains slowly or not at all, you likely have a clog. Use a toilet plunger with a flange to create a good seal in the toilet bowl. Push down slowly, then pull up quickly to create suction. Repeat this motion vigorously for 15-20 strokes. If plunging doesn't work, try a toilet auger to break up deeper clogs.
  6. Swap Parts, Restore Flow. If adjustments don't solve the problem, you may need to replace the flapper, chain, or fill valve entirely. Turn off water at the shutoff valve behind the toilet, flush to empty the tank, and install new parts according to manufacturer instructions. Most toilet repair kits include all necessary components and detailed instructions.