Invisible leaks: how to find the one inflating your bill

A visible leak fixes itself: someone sees it, someone complains, someone calls the plumber. The ones that ruin bills are invisible: the toilet flapper that no longer seals, the joint dripping inside a wall, the tank valve that never fully closes. Here are the three home tests plumbers use, in order.

Test 1: the still meter (10 minutes)

• Close EVERY tap and appliance that uses water. Washer and filters included.
• Photograph the meter reading, red decimals included.
• Use no water for 30 minutes. Not even the toilet.
• Look again: if the numbers moved, there is an active leak somewhere.

If your meter has a small flow star or wheel, it is even easier: with everything closed that wheel must be completely still. If it creeps, something is passing water.

Test 2: dye in the tank (15 minutes)

The toilet is suspect number one: a worn flapper passes a continuous silent thread of water from tank to bowl. Drop food coloring into the TANK, not the bowl, and wait 15 minutes without flushing. If the bowl shows color, the flapper is done. The part costs under 150 pesos and the leak was wasting 100 to 400 liters a day.

Test 3: overnight (one night)

For small leaks the 30-minute test misses: meter reading before bed, zero consumption overnight, reading on waking. Any difference is a leak. A single 10 liters per night is 3,650 liters a year.

Does the hot-water wait count as a leak?

Technically no: the water passes the meter and leaves through the shower. But it behaves exactly the same: liters you pay for and never use, every day. The difference is this "leak" is not fixed with traditional plumbing but by returning the water to the heater before opening the tap. Size it with our calculator: in the average home it is bigger than any toilet leak.

If all three tests come back clean and the bill is still high, the problem is not a leak: it is consumption. Start with the 20 ways to save, ranked by impact.