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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- Toilet flapper kit Shop →
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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 Phoenix, tap water is very hard (320–450 ppm). Phoenix has some of the hardest water in the U.S., sourced from Colorado River and groundwater. Mineral deposits are severe and visible within weeks on fixtures. Water heaters fail quickly (6–8 years). Water softeners are nearly universal among informed homeowners.
Plumbers in Phoenix typically charge $90–150/hr. Most homeowners budget $800–2,500 for common repairs like fixture replacement, drain clearing, or valve repairs.
Arizona has minimal licensing for plumbers. Cities (Phoenix) require permits. Homeowners can perform plumbing with permits.
Majority post-1990s construction. Copper is standard. PEX is increasingly used. Hard water means sediment buildup in water heaters is severe; flushing annually is essential. Slab-on-grade is common; underground pipe leaks are expensive repairs.
DIY in Phoenix: Phoenix is very DIY-friendly. Arizona's permissive licensing and culture support homeowner work. Hard water management and HVAC maintenance are common DIY focuses. Cooling system care is critical and often DIY-maintained.
- 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.
Describe the problem. Uncle AI asks the right questions and tells you exactly what's broken — and whether you should fix it yourself or call someone in Phoenix.
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