Quick answer
Turn off the water supply, flush the toilet, and inspect the fill valve and supply line. Replace or adjust parts as needed to restore water flow to the tank.
Confirm the symptom
- Tank remains empty after flushing
- No water enters the tank when the toilet is turned on
- Toilet bowl fills but the tank does not
- Water supply valve is fully open but no water enters the tank
- No water pressure in the tank
Tools and prep
- Adjustable wrench
- Screwdrivers (flathead and Phillips)
- Plumber's putty or Teflon tape
- Bucket or towel
- Flashlight
- Turn off water supply before starting work
- Wear rubber gloves to avoid contact with dirty water
Step-by-step troubleshooting
- Check Water Supply ValveDo: Locate the shut-off valve near the base of the toilet and ensure it is fully open.Observe: Valve is open but water still does not reach the tank.Means: The issue may be with the fill valve or supply line.Next: Inspect the fill valve.
- Inspect the Fill ValveDo: Look for cracks, debris, or mineral buildup in the fill valve. Clean or replace if necessary.Observe: Fill valve is clogged or damaged.Means: A faulty fill valve is preventing water from entering the tank.Next: Replace or clean the fill valve.
- Check the Float MechanismDo: Ensure the float is not stuck or damaged. Adjust the float height if needed.Observe: Float is stuck or set too low.Means: The float is not allowing the fill valve to open properly.Next: Adjust or replace the float.
- Test the Supply LineDo: Use an adjustable wrench to check for leaks or kinks in the supply line connecting the shut-off valve to the fill valve.Observe: Supply line is kinked or leaking.Means: A damaged supply line is restricting water flow.Next: Replace the supply line.
- Check for ClogsDo: Remove the fill valve and inspect for clogs in the inlet screen or valve seat.Observe: Clogs are present in the inlet screen or valve seat.Means: Debris or mineral buildup is blocking water flow.Next: Clean the inlet screen and valve seat.
- Test Water PressureDo: Check the household water pressure using a pressure gauge. Low pressure may prevent the tank from filling.Observe: Water pressure is below 20 psi.Means: Low household water pressure is affecting the toilet's performance.Next: Contact a plumber to assess the home's water pressure.
Common causes
| Cause | Likelihood | Difficulty | Part often needed |
|---|---|---|---|
| Faulty Fill Valve The fill valve may be clogged, damaged, or improperly adjusted, preventing water from entering the tank. | Common | Easy–Medium | Fill valve |
| Clogged Inlet Screen Mineral deposits or debris can block the inlet screen, restricting water flow. | Common | Easy | Inlet screen cleaning |
| Kinked or Leaking Supply Line A damaged or kinked supply line can prevent water from reaching the tank. | Sometimes | Easy | Supply line |
| Low Water Pressure Insufficient household water pressure may prevent the tank from filling properly. | Rare | Hard | Water pressure regulator |
| Stuck or Damaged Float A stuck or improperly adjusted float can prevent the fill valve from opening. | Sometimes | Easy | Float assembly |
| Closed or Faulty Shut-Off Valve The shut-off valve may be partially closed or damaged, restricting water flow. | Sometimes | Easy | Shut-off valve |
| Faulty Flapper Valve A faulty flapper valve can cause the tank to continuously drain, making it appear as if no water is entering. | Rare | Easy | Flapper valve |
Parts matching
Common replacement parts for a toilet not getting water to the tank include:
- Fill valve (also known as a ballcock)
- Supply line (flexible water line)
- Float assembly
- Shut-off valve
- Inlet screen or filter
- Flapper valve
Purchase parts that match your toilet model for proper fit and function.
When to call a professional
- Water continues to leak after replacing parts
- Low water pressure affects multiple fixtures
- You are unable to locate or access the shut-off valve
- Damage to the toilet tank or bowl is present
- The issue persists after following all troubleshooting steps
FAQ
How do I know if my fill valve is faulty?
If the tank does not fill with water after flushing and the shut-off valve is open, the fill valve may be faulty. Check for clogs, cracks, or improper adjustment.
Can I use any fill valve for my toilet?
It is best to use a fill valve that matches your toilet model for compatibility and performance. Check the manufacturer's recommendations.
Why is there no water pressure in my toilet tank?
Low household water pressure or a clogged inlet screen can reduce water pressure in the tank. Check the pressure gauge and clean the inlet screen if necessary.
How often should I replace the supply line?
Supply lines should be inspected annually for leaks or wear. Replace them every 5–10 years to prevent failures.
What should I do if the float is stuck?
Lift the float gently to see if it moves freely. If it is stuck or damaged, clean or replace the float assembly.