Symptoms
- Refill takes noticeably longer than it used to
- Weak trickle sound instead of a steady fill
- Other fixtures in the house may also be slow
- Toilet is unusable for a second flush for several minutes
Likely causes
- CommonPartially closed shutoff valveThe valve behind the toilet isn't fully open, restricting flow.
- CommonClogged fill valve inlet screenSediment has built up in the small filter inside the fill valve.
- PossibleLow household water pressureA house-wide pressure drop affects how fast any fixture refills.
- PossibleKinked or narrow supply lineA pinched or too-narrow line restricts water flow to the tank.
What to do
- Make sure the shutoff valve is turned fully open (all the way counterclockwise).
- Check other faucets to see if slow flow is a whole-house issue rather than just this toilet.
- Turn off the water, remove the fill valve cap, and rinse out any sediment in the inlet screen.
- Inspect the supply line for kinks or a very narrow diameter, and replace with a properly sized braided line if needed.
- Replace the fill valve entirely if flow is still slow after cleaning it.
Tools and parts
- Adjustable wrench
- Small cup
Toilet fill valveSearch: “universal toilet tank fill valve”
When to call a pro
Call a plumber if slow refilling is happening house-wide, since that points to a supply-side pressure or pipe issue.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.