Fix a Running Toilet in 20 Minutes

A running toilet is one of those household problems that's easy to ignore — until you see the water bill. A toilet that runs continuously can waste 200 gallons of water per day. That's not just expensive; it's poor stewardship of a precious resource.

The good news: most running toilet problems are caused by one of two worn parts, and fixing either takes less time than driving to the hardware store.

Diagnosing the Problem

First, remove the tank lid and set it aside safely. Look inside while the toilet is running.

The flapper is likely the culprit if: you can see or hear water flowing into the bowl continuously, or if you add a few drops of food coloring to the tank and it appears in the bowl without flushing.

The fill valve is likely the culprit if: water is running over the top of the overflow tube (the tall tube in the center of the tank).

Repair 1: Replacing the Flapper

The flapper is the rubber seal at the bottom of the tank. It wears out over time and no longer seats properly, allowing water to leak into the bowl.

Parts needed: Universal flapper (~$5–8 at any hardware store)

1. Turn off the water supply valve at the wall (turn clockwise).
2. Flush the toilet to empty the tank.
3. Unhook the old flapper from the overflow tube pegs and disconnect the chain from the flush handle arm.
4. Attach the new flapper to the overflow tube pegs (it should snap on).
5. Connect the chain to the handle arm, leaving ½" of slack.
6. Turn the water back on and let the tank fill.
7. Test: flush and observe. The flapper should seal completely.

The whole job takes 10 minutes and costs under $10.

Repair 2: Adjusting or Replacing the Fill Valve

If water is overflowing into the overflow tube, the fill valve isn't shutting off properly. Sometimes this is a simple adjustment; other times the valve needs replacement.

Try adjusting first:

• On older ballcock-style valves, bend the float arm down slightly to lower the shutoff point.
• On newer fill valves (Fluidmaster style), turn the adjustment screw on top counterclockwise to lower the cutoff level.

The water level in the tank should be approximately 1 inch below the top of the overflow tube.

If adjustment doesn't fix it, replace the fill valve:

Parts needed: Replacement fill valve ($10–15, Fluidmaster 400A is the standard)

1. Turn off water and flush to empty.
2. Disconnect the water supply line from the bottom of the tank.
3. Use an adjustable wrench to remove the locknut on the bottom of the tank.
4. Lift the old fill valve out.
5. Set the height on the new valve per the instructions (typically: overflow tube height + 1 inch).
6. Insert and hand-tighten the locknut from below. Firm it with the wrench — don't overtighten.
7. Reconnect the supply line. Reconnect the refill tube to the overflow tube.
8. Turn water on. Let fill. Check water level. Adjust if needed.

On Simple Skills

There's a particular satisfaction in fixing something that was broken. It's a small thing — a toilet flapper — but it represents something larger: the willingness to learn, the patience to diagnose before reacting, the confidence that problems can be solved.

These skills compound over a lifetime. Each small repair teaches something. Each piece of knowledge passed to your children or your neighbor is a small act of generosity.

Pray before you work. Work as if it matters. Because it does.