If you've ever had the misfortune of having a water pipe freeze and burst, you know that's an experience you only want to have once in a lifetime. It's not just the aggravation and cost of fixing the pipe itself, it’s the damage the burst pipe does to the rest of your home. Walls, ceilings, floors and personal possessions stored in the basement or crawl space can all be ruined. Damages are sometimes covered by insurance, but depending on circumstances, you might just be on your own. Plus, even if your home insurance does cover the damage, you're still going to be living in a construction zone until the mess gets repaired. Obviously, making sure your pipes don't freeze is a much better option.
Draining the Lines
Before cold weather, shut off the valves supplying your outside water lines. Individual supply lines running to the outside (hose bibs for example) will usually have a shut off valve on the inside of your home, close to where the supply goes outside. Drain the outside lines by opening the tap and then leave it the open position. This will allow any small amount of water that might be left in the line to freeze and expand without causing any damage.
The major damage from frozen pipes comes when a home is unoccupied during a cold spell and the pipes freeze solid. When the pipes warm up, water flows out of the broken pipes into the walls and down through ceilings creating thousands of dollars of damage. If you're going to be away from your home for a while, you can prevent this from happening by actually shutting off the water supply to your entire home, then opening the taps and draining the water in the pipes. (Be sure you shut off your hot water tank as well.) This way, even if your furnace does stop working while you're away, there isn’t any water in...