If you live in an area where the temperature ever drops below freezing, even if it does so for only a few days, you need to do several things to protect your plumbing.
First, make sure that you know where you water shut-off valve is — just in case you need to get to it in a hurry!
If any of your pipes are exposed to the air (indoor or outdoor), wrap some insulation around them. It might not be the aesthetic look you want with your decor, but it's better than waterlogged carpets and furniture from broken pipes.
Credit: ©iStockphoto.com/nsj-imagesThis goes for pipes that are hidden, but exposed, in an under-the-sink cabinet. If you can see the pipes, you need to cover them.
Insulate your hot water heater, whether it's in a cold, dank basement or stuffed in a utility closet. An easy way to insulate it is to purchase a specially made blanket at your local hardware or big box store. Or, you can use duct tape and insulation.
Turn off the water supply to exterior faucets and drain them. In places where the temperature gets really low, use an insulated cover on the hose bibbs (outdoor faucets for your garden hoses). You can find some really cute covers in gardening catalogs that look like frogs or ladybugs. Or, you can use foam pipe insulation.
Turn off the water supply to sprinkler systems. You also need to use compressed air to blow any water out of the lines. Otherwise, they might freeze and burst.
Even if you're boarding the dog and stopping the newspaper when going on a vacation, you should leave your furnace set no lower than 55 degrees.
If you are a snowbird, who lives in Florida or another warmer state during the winter months, you might need to shut off the water supply. Also drain the entire plumbing system, unless you have a caretaker of some sort coming in to check the plumbing and pipes.