How to replace a toilet fill valve that keeps running

Difficulty Easy Time 1-2 hours Materials $19–$50 Steps 7
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Easy1-2 hours
Shut off the water supply before starting.
Do it yourself
$19–$50
parts & materials, about 1-2 hours of your time
Hire a pro
$150–$250
typical all-in price
Doing it yourself could save roughly $100
Rough estimates for guidance only — actual costs vary by job, materials and local prices. Get real quotes.

Tools you'll need

Adjustable wrenchScrewdriverTowel

Parts & materials

Toilet fill valve
Typically need: 1
$10-$25
per each
Tank-to-bowl gasket
Typically need: 1
$2-$5
per each
Water supply line (if needed)
Typically need: 1
$5-$15
per each
Plumber's tape
Typically need: 1
$2-$5
per each

Estimated materials total: $19–$50. Prices vary by region and retailer.

Step by step

  1. 1 Shut off the water supply Locate the shut-off valve behind the toilet and turn it clockwise to stop the water flow. 5 min
  2. 2 Drain the toilet tank Flush the toilet to empty the tank and use a towel to soak up any remaining water. 10 min
  3. 3 Remove the old fill valve Use an adjustable wrench to disconnect the water supply line and unscrew the old fill valve from the tank. 15 min Adjustable wrench
  4. 4 Install the new fill valve Follow the manufacturer's instructions to install the new fill valve, ensuring it is securely fastened. 20 min Screwdriver
  5. 5 Reconnect the water supply line Attach the water supply line to the new fill valve and use plumber's tape to ensure a tight seal. 10 min Adjustable wrench
  6. 6 Turn on the water supply Turn the shut-off valve counterclockwise to restore water flow and check for leaks. 5 min
  7. 7 Test the toilet Flush the toilet and ensure the fill valve operates correctly without running continuously. 5 min

Permits, safety & disposal

Safety rules
  • Shut off the water supply before starting.
  • Use proper tools to avoid injury.
Legal disposal
  • Old fill valve and parts can be disposed of in regular trash.
Check locally

Confirm any local plumbing codes with the Naperville building authority.

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This guide is AI-generated for general help and may not fit your exact situation. Know your limits — when in doubt, hire a licensed pro.

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