- Shut off the main water valve. It may be located inside or outside of your house. If you cannot locate the main source, contact your local water supply company.
- Drain pipes of water. Turn on every water fixture in the house until the water stops running. Drain all water outside of the house by attaching a hose to a sill cock or basement faucet. Open all faucets and flush all toilets in the house, starting with the top floor and working your way down. Remove the toilet tank cover and continue flushing until all of the water has drained out.
- Force the water out. Use an air compressor to force any remaining water out of the pipes. Starting on the top floor, apply bursts of air to the main drains for several seconds each.
- Drain appliances. Turn on the dishwasher and allow it to run to clear water from the drain line. Run both hot and cold water through the washing machine to flush out all the lines. Open the shut-off valve beneath each toilet to allow compressed air to blow out water for a few seconds each, then close the valve.
- Extra Protection: Pour anti-freeze into all sink and bathtub drains. Add a small amount of anti-freeze to each toilet tank.
- When you are ready to use the water again, turn on the main water valve and let each fixture run until the pipes are full.
Tip: During extreme cold weather, let your faucets drip to help prevent the pipes from bursting. If you do not want to waste any water, an alternative is turning off your water and opening your faucets. This releases excessive pressure and decreases your chances of busted pipes.
Sources: This Old House, The Weather Channel, Do It Yourself