Toilets: Common Issues and Fixes (Troubleshooting Guide)

On this page

Quick answer

To fix a running toilet, adjust the flapper or float. For clogs, use a plunger or auger. Always turn off the water supply before repairs.

Turn Off Water Supply
Do: Locate and turn the shut-off valve clockwise to stop water flow.
Observe: Water stops entering the tank.
Means: Safe to proceed with repairs.
Next: Inspect the toilet components
Check for Clogs
Do: Use a plunger to try to dislodge the clog.
Observe: Water level in the bowl drops and flushes normally.
Means: Clog is cleared.
Next: Flush the toilet to test
Use a Toilet Auger
Do: Insert the auger into the bowl and crank to break up the clog.
Observe: Clog is removed and water drains freely.
Means: Clog is cleared.
Next: Flush the toilet to test
Adjust the Flapper
Do: Lift the flapper and check if it closes properly. Adjust the chain if it's too tight or loose.
Observe: Flapper closes securely after flushing.
Means: Water stops running.
Next: Test the toilet by flushing
Adjust the Float
Do: Lower or raise the float to adjust the water level in the tank.
Observe: Water level is at the correct height.
Means: Tank fills properly.
Next: Turn the water supply back on
Check for Leaks
Do: Inspect the base of the toilet for water or dampness.
Observe: Water is present around the base.
Means: Toilet may need to be resealed or replaced.
Next: Tighten bolts or call a professional

Cause	Likelihood	Difficulty	Part often needed
Running Toilet Flapper not closing properly or float set too high.	Common	Easy	Flapper or float
Clogged Toilet Blocked drain line or excessive waste.	Common	Easy–Medium	Toilet auger
Low Water Level Float set too low or water supply valve closed.	Common	Easy	Float
Toilet Making Noise Mineral buildup or faulty fill valve.	Sometimes	Easy–Medium	Fill valve
Leaking Toilet Cracked porcelain or loose bolts.	Sometimes	Medium	Wax ring or bolts
Weak Flush Clogged jets or insufficient water in the bowl.	Sometimes	Easy	Water level adjustment

Common replacement parts for toilets include:

Purchase parts that match your toilet model for the best fit and performance.

How do I know if my toilet is leaking?

Place food coloring in the tank and wait 15 minutes. If color appears in the bowl without flushing, there's a leak.

Can I replace a toilet flapper myself?

Yes, turn off the water supply, flush to drain the tank, then replace the flapper with a new one.

Why does my toilet keep running?

A faulty flapper or float is usually the cause. Adjust or replace these parts to stop the water from running.

How often should I replace my toilet wax ring?

Replace the wax ring if the toilet is leaking or being removed and reinstalled.

What should I do if plunging doesn't unclog my toilet?

Use a toilet auger to clear the clog. If it still doesn't work, call a professional plumber.