Why is my water bill so high? Check your toilets first

The water bill arrives and it is double what it was. Nobody filled a pool. Nobody had houseguests. The first place to look is the toilets, and the test takes twenty minutes and a bottle of food coloring.

The dye test

1. Take the lid off the toilet tank. Do not flush.
2. Put 8 to 10 drops of food coloring, or a dye tablet from the hardware store, into the tank water.
3. Wait 20 to 30 minutes. Do not use the toilet.
4. Look in the bowl. If any color has reached the bowl, the flapper at the bottom of the tank is not sealing, and water is leaking from the tank into the bowl and down the drain, all day and all night.

Test every toilet in the house. In a two- or three-bath home it is common for exactly one to be leaking, and it is usually the one that gets used least.

Fixing a leaking flapper

The flapper is the rubber disc on a hinge at the bottom of the tank, connected to the flush handle by a chain. In Florida’s warm, chlorinated water, flappers get stiff and warped in a few years.

• Turn off the small supply valve behind the toilet and flush to empty the tank.
• Unhook the chain and pull the flapper off its pegs. Take it to the hardware store to match it, or note whether the flush valve opening is 2 inches or 3 inches.
• Wipe the seat where the flapper sits. Mineral buildup there causes leaks as often as the flapper itself.
• Install the new flapper, reconnect the chain with a little slack, turn the water on, and repeat the dye test.

If the toilet still leaks with a new flapper and a clean seat, the flush valve seat is pitted or the tank-to-bowl gasket is failing. That is a plumber-sized job, and on an older toilet it is often the point where a replacement makes more sense than the repair.

The other tank leak: the fill valve

Look at the tall tube standing in the tank (the overflow tube). The water line should sit about an inch below its top. If water is trickling into the overflow tube, the fill valve is set too high or is failing to shut off, and the toilet is sending clean water straight to the sewer.

Most fill valves have a screw or a clip to lower the float. If adjusting it does not stop the flow, the fill valve needs replacing. That is a common homeowner repair, but the supply line and the shutoff valve behind the toilet are often original and brittle; if either one looks corroded, have it replaced at the same time rather than risk a snapped valve.

If the toilets pass: read the meter

The meter tells you whether the house is using water when it should not be.

1. Turn off every faucet, the ice maker, the irrigation controller, and any pool autofill. Make sure nobody runs water for the next hour.
2. Open the meter box at the street. Note the reading, and look for a small triangle, star, or dial on the meter face. That is the leak indicator.
3. Wait 30 to 60 minutes and read it again.

If the reading changed or the indicator moved, water is flowing somewhere. Close the main house valve and check the meter again. If the meter stops, the leak is inside the house or under the slab. If the meter keeps moving with the house valve closed, the leak is in the service line between the meter and the house, or in the irrigation.

When the leak is in the slab

Homes here sit on concrete slabs with the hot and cold lines running under or through them. A slab leak shows up as a warm spot on the tile, a sound of running water with everything off, a damp patch at the base of a wall, or simply a meter that will not stop. Finding it is a job for leak detection equipment, not guesswork, and the fix ranges from a spot repair to rerouting the line overhead. Older copper lines in Cape Coral and Fort Myers homes from the 1970s and 80s are frequent offenders.

The one-hour checklist

• Dye test every toilet.
• Look for water trickling into each overflow tube.
• Walk the yard for a sprinkler zone that never stops, or a soggy spot.
• Check under sinks and behind the washing machine for drips.
• Read the meter with everything off, then again with the house valve closed.

If you get through that list and the meter is still moving, you have done the homework a plumber would have done first. Send us what you found and we will pick up from there.