What is the most common source of indoor leaks?

• A. Water heater
• B. Shower
• C. Faucet
• D. Toilet

Answer: (D)

Toilets are the most common source of indoor leaks because they hold a lot of water in their tank and have several parts that can wear or fail over time. The flapper or flush valve can stop sealing properly, letting water flow from the tank into the bowl continuously. The fill valve can fail and keep refilling the tank even when no one is flushing, wasting water every minute. A worn wax ring at the base can allow water to seep onto the floor, especially after flushing. Because these components are inside a frequently used fixture, small faults add up to a substantial amount of wasted water, making leaks from toilets more common than leaks from other fixtures.

Faucets and showers do leak, but they usually leak as drips or small streams that don’t waste water as rapidly or persistently as a running toilet. Water heater leaks tend to indicate a more serious issue and aren’t as routinely seen as ongoing indoor leaks. If you want to check quickly, a simple dye test in the toilet tank can reveal a running toilet, and you’ll know the most likely source is the toilet if you see color in the bowl long after flushing.