After flushing, a toilet tank should refill automatically within about a minute. When the tank fails to refill, the toilet can’t flush again—so it becomes temporarily unusable. Fortunately, most refill problems are caused by a shutoff issue or a malfunctioning tank component rather than a serious plumbing failure.
In most cases, restoring water flow involves checking the supply valve or adjusting or replacing the fill valve inside the tank. Start by confirming the symptoms below, then follow the steps to restore normal operation.
Quick Answer
A toilet that won’t fill with water is usually caused by a closed supply valve, kinked supply line, or failed fill valve. Restoring water supply or replacing the fill valve typically solves the problem.
Common Signs the Toilet Tank Isn’t Filling
- Tank remains empty after flushing
- No sound of water entering the tank
- Toilet flushes once and then stops working
- Handle moves normally but nothing happens afterward
- Very little or no water visible in the tank
Likely Causes
Most refill failures result from:
- Shutoff valve partially or fully closed
- Kinked or blocked water supply line
- Debris clogging the fill valve
- Stuck float mechanism
- Failed or worn fill valve
- Low household water pressure
Tools & Materials
You may need:
- Adjustable wrench
- Small cup or sponge
- Replacement fill valve (if needed)
- Towel or bucket
- Rubber gloves
Have towels ready in case water spills when disconnecting supply components.
Step-by-Step: How to Fix a Toilet That Won’t Fill
1. Check the Water Shutoff Valve
Locate the shutoff valve beneath the toilet. Turn it counterclockwise to confirm it is fully open. Valves sometimes get bumped during cleaning or repairs.
Flush again and listen for refilling.
2. Inspect the Supply Line
Check the flexible supply tube connecting the wall valve to the tank.
Look for:
- Sharp bends or kinks
- Visible leaks
- Mineral buildup at connections
Straighten the line if necessary and confirm water flow is restored.
3. Check the Float Position
Remove the tank lid and inspect the float. If the float is stuck in the raised position, the fill valve will remain closed.
Gently move the float downward and flush again to see whether water begins flowing.
4. Clean the Fill Valve
Debris or sediment can block the fill valve inlet.
Turn off the water supply, remove the fill valve cap according to manufacturer instructions, and briefly turn the water back on to flush debris from the valve.
Reassemble and test.
5. Replace the Fill Valve if Necessary
If water still does not enter the tank, the fill valve may have failed.
Shut off the water supply and disconnect the supply line beneath the tank.
Remove the old fill valve and replace the fill valve following manufacturer instructions. Reconnect the supply line and restore water flow.
6. Test Tank Refill
Turn the water supply back on and allow the tank to fill.
The water level should stop about 1/2 inch below the top of the overflow tube.
Flush several times to make sure it’s refilling properly.
When the Problem May Be More Serious
If the toilet still does not refill, the issue may involve:
- Extremely low household water pressure
- Blocked plumbing supply lines
- Valve failure inside the wall
- Larger plumbing system problems
If other fixtures also lack water flow, call a plumber.
Preventing Future Fill Problems
- Periodically check shutoff valves to make sure they work smoothly
- Replace aging water supply lines
- Flush sediment from plumbing after water service work
- Replace worn fill valves before they fail
To Hire a Plumber…
If the repair turns out to be more complicated than expected, you can always find a plumber near you.
For hiring advice, see Trade Secrets for Hiring the Right Plumber.
Related Articles
If you’re not sure what’s causing the problem, see our
Toilet Repair and Troubleshooting Guide for a complete diagnostic overview.Also see:
- How to Fix a Running Toilet
- Toilet Bowl Water Level Too High or Too Low: How to Fix It
- How to Fix a Toilet That Fills Slowly
- Toilet Repair Costs
