The $5 Part Causing Your $200 Water Bill: How to Fix a Running Toilet Fast

An essential feature on The $5 Part Causing Your $200 Water Bill: How to Fix a Running Toilet Fast, covering expert perspectives.

If adjusting the float height fails to stop water from spilling down the overflow tube, the fill valve's internal seal has failed or sediment has clogged the shut-off diaphragm. Replacing the entire assembly with a universal unit takes less than fifteen minutes.

With the supply valve turned off and the tank emptied, place a small plastic bucket or towel directly beneath the water inlet on the tank's underside. Loosen the coupling nut connecting the water supply line to the bottom shank of the fill valve using channel-lock pliers. Next, unscrew the plastic mounting nut that clamps the valve shank to the bottom of the porcelain tank.

Pull the old fill valve out from inside the tank. Adjust the height of your new universal fill valve so that the cap sits roughly three inches above the top of the overflow pipe when installed. Slide the rubber washer onto the threaded shank, push the unit down through the tank hole, and hand-tighten the plastic locknut underneath until snug, adding a quarter turn with pliers. Do not overtighten; excess pressure can crack the porcelain base. Reattach the supply line, clip the small refill tube into the top of the overflow pipe, and turn on the water to test your handiwork.