What's actually causing this
Toilets run when water continuously trickles from the tank into the bowl. The two most common culprits are a worn-out flapper that doesn't seal properly, and a fill valve that's stuck open or set too high.
What you'll need
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Step-by-step fix
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1
Diagnose the problem
Lift the tank lid and add a few drops of food coloring. If color appears in the bowl within 10 minutes without flushing, the flapper is leaking.
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2
Turn off the water supply
Turn the shutoff valve behind the toilet clockwise. Flush once to empty the tank.
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3
Replace the flapper
Unhook the old flapper from the overflow tube pegs. Snap the new flapper in place and reconnect the chain — leave about half an inch of slack.
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4
Adjust the fill valve
If water is running over the overflow tube, the water level is too high. Adjust the float arm or float ball downward until the water sits 1 inch below the top of the overflow tube.
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5
Turn water back on and test
Slowly open the shutoff valve. Let the tank fill and listen for any continued running after the fill cycle completes.
In Nashville, tap water is moderate (100–160 ppm). Nashville's water is moderately hard. Scale buildup is noticeable but not severe. Water softeners are common in maintenance-focused homes.
Plumbers in Nashville typically charge $90–150/hr. Most homeowners budget $800–2,500 for common repairs like fixture replacement, drain clearing, or valve repairs.
Tennessee requires state licensing for master plumbers. Nashville requires permits. Homeowner exemptions limited.
Mix of pre-1950s and post-1980s construction. Older homes may have galvanized piping with corrosion. Newer homes have copper or PEX. Moderate hardness means fixtures last longer than hard-water areas. Freeze-thaw cycles (though mild) can cause burst risk.
Nashville gets occasional freezes, but extended deep cold is uncommon. Pipes in exterior walls or unheated crawl spaces are the primary risk. A few nights below freezing per year means basic insulation is prudent.
DIY in Nashville: Nashville's moderate licensing and growing DIY culture support homeowner repairs. Many people handle simple work. Rapid growth toward a major metro means modernizing DIY skills is becoming more important.
- The tank or bowl has visible cracks.
- The toilet rocks or is loose at the base — this may indicate a wax ring failure.
- Water appears on the floor around the base after flushing.
Let Uncle AI diagnose it first.
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