There can leak as much as 4000 gallons a month. That is how much water a family often uses for the whole month! That period can double your water bill. Obviously, you must shut off the water service into your home prior to working on many of these below spots around your home. Even if the fixture has its own shut-off valve, you will never go wrong closing the main shut-of line.
Washing machine Check hoses regularly for bulging, cracking, fraying, and leaks around hose ends. Replace the hose if a problem is found or every three to five years as part of a proactive maintenance program. To help make sure the hose doesn't kink, leave at least four inches between the water connection and the back of the washing machine. Even if you cant find a source of water, the washing machine may only leak if the machine has been running.
Water heater most water heaters last eight to 15 years. Wet spots on the floor or a rusted tank may signal a leak. Water heaters should be installed on the lowest level of the home, next to a floor drain, or inside a drain pan piped to the floor drain.
Sump pump Battery-operated back-up sump pumps can help protect against power failure or failure of the primary pump. Test the sump pump before the start of each wet season. Sump pumps are not intended to last more than 10 years and must have some components replaced or serviced within those 10 years.
Fire Suppression (sprinkler) systems- Many newer homes have these installed to prevent fire, and they can leak, often at the sprinkler heads. Make sure that they are all tightened.
Humidifiers will often have water standing beneath them as a sign of a leak.
Water Softeners - May run constantly if they have a leak. You are likely to hear the sound of running water when you get close to them.
Outdoor faucets - These have a gasket in them similar to sinks that can be easily replaced.
Swimming Pools - May have an automatic fill that does not require you to put a hose in the pool to add water, but may be adding water without your knowledge.