When cold weather sets in, the plumbing system becomes one of the most vulnerable parts of your home. The water in your pipes will expand as much as 9 percent when it freezes, which might cause them to burst. That damage may not be apparently immediately -- the water may not be released until ice thaws. Burst pipes can lead to anything from a minor mop-up to a major repair. Catching the burst pipe early is key to preventing the damage from starting when you are away from the home, where water can flow uninterrupted for hours. To tell if you have a burst pipe, count on your house's own clues.
Listen for dripping water within your walls and follow the sound to its source. A well pipe kept running during frigid weather might cause a burst pipe. In some cases, the water might flood the basement floor.
Hold a paper towel under outdoor faucets and feel for moisture. Outdoor fixtures are more susceptible to freezing and leaks from burst pipes.
Examine crawlspaces and garages for telltale puddles on the ground or floor, using a flashlight if necessary. The pipes in these unheated areas are prone to freezing, so if they burst, the initially undetected damage can eventually become substantial.
Run the faucets in the kitchen and bathrooms. A burst pipe could compromise the flow to these fixtures. Take note if the water appears to run slowly, or not at all, or if water from the hot-water tap takes an unusually long time to warm up. If you need to run more water than usual for hot showers, dish washing and other tasks, this is a sign of a burst pipe.
Examine the ceilings where you suspect a burst pipe. Spilled water will form a stain on the ceiling's surface, and a musty smell might accompany the stain. In extreme cases, the ceiling tile or drywall might crack, causing water to flood the floors below.
Locate the water meter outside your home. Open the meter and note if the dials are turning. If they are, the leak is likely to have generated on your property.