My Toilet Keeps Running: Why It Happens in Phoenix and How to Fix It

When a toilet keeps running, the cause is almost always one of three parts inside the tank: a worn flapper that no longer seals, a fill valve that will not shut off, or a float set so high that water spills into the overflow tube. In Phoenix, hard water at 16 to 20 grains per gallon wears out all three faster than in most of the country. The fix is usually a small part and thirty minutes, but a running toilet left alone can waste more water in a month than the rest of the house uses.

How to Tell Why Your Toilet Keeps Running

Take the tank lid off and look. If the water level is above the top of the overflow tube, the float is set too high or the fill valve is failing. If the water level is fine but you hear a hiss or the tank refills every few minutes on its own, the flapper is leaking water into the bowl. A quick test: put a few drops of food coloring in the tank, wait fifteen minutes without flushing, and check the bowl. Color in the bowl means the flapper is the problem. If the fill valve runs constantly and never shuts off, that valve is worn or has grit stuck in it.

Why Phoenix Hard Water Makes a Toilet Keep Running

Our water carries a lot of dissolved calcium and magnesium. Over time it leaves a chalky scale on the flapper seat, so the rubber cannot seal flat. It stiffens the flapper itself. It builds up inside the fill valve until the valve sticks open. It even coats the float so it sits lower in the water and tells the valve to keep filling. We covered the bigger picture in our post on why Phoenix hard water is destroying your pipes, and a running toilet is one of the earliest symptoms we see in a home without a water softener. If you have replaced a flapper twice in three years, hard water is why.

The Fixes, From Easiest to Hardest

• Adjust the float. On a ball float, bend the arm down slightly. On a cup float, turn the adjustment screw or slide the clip down. The water line should sit about an inch below the top of the overflow tube.
• Replace the flapper. Shut off the supply, flush, unhook the old flapper, clean the seat with a scrub pad to remove scale, and hook on the new one. Match the size, since a two-inch flapper will not seal a three-inch flush valve.
• Replace the fill valve. Shut off the supply, drain the tank, disconnect the supply line, remove the old valve from the bottom of the tank and install the new one. Fifteen minutes for a plumber, maybe an hour for a first-timer.
• Replace the flush valve. If the seat itself is pitted or cracked, the tank has to come off. This is the point where most people call us.

A Call from a Home in Arcadia

A homeowner called our dispatcher because her water bill had jumped and she could hear the guest toilet refilling at night. Nobody had used that bathroom in weeks. Our plumber ran the dye test and found the flapper leaking, but when he pulled it the flush valve seat underneath was so scaled and pitted that a new flapper would have leaked within a month. He replaced the whole flush valve, the flapper and the fill valve in one visit from the parts on the truck, then showed her where the water level should sit. She had the flat-rate price before he started, so there was no surprise at the end. The high bill went back to normal the next cycle.

When a Running Toilet Means Something Bigger

Here is the honest counterpoint. Sometimes the toilet is not the only thing running. If you fix the toilet and the water meter still spins with everything shut off, you may have a leak somewhere else, including under the slab, which is common in older Phoenix homes. And if the toilet is fifteen or twenty years old with a cracked tank, a rusted bolt set or a wobbly base, putting new guts in it is a short-term patch. A modern 1.28-gallon toilet uses a fraction of the water of an old 3.5-gallon model, and in that case we will tell you that toilet installation is the smarter path than another repair.

Get Your Running Toilet Fixed by Phoenix Plumbing Co.

Phoenix Plumbing Co. has been family owned since 2012, with three generations working in the business. A live Phoenix dispatcher answers the phone, our trucks are stocked to finish nine out of ten jobs on the first visit, and you see the flat-rate price before we lift a wrench. Every repair comes with a written workmanship warranty and a 40-point inspection so we catch the next problem before it becomes one. If your toilet keeps running, or you want a plumbing inspection of the whole house, call Phoenix Plumbing Co. at 602-834-1208.