Stop your drain pipe from freezing with this simple Letsfixit guide. Most homes have either CPVC, copper or galvanized water supply pipes. However, if any of these three types of pipes are not adequately insulated, or if there is a heavy freeze, the water inside the pipes can burst creating extensive damage in the home. Draining the pipes is always the best bet against bursts, especially when leaving the home vacant for extended periods of time. The draining process is fairly simple to do and isn’t time consuming.
Turn off the house's main shut-off valve by turning the valve handle clockwise a quarter turn. When closed, the handle will be 90 degrees to the water pipe.
Locate the lowest faucet in the house. This is usually in the basement or buildup area. Attach a flexible garden hose to the faucet, and run the end of the hose outside. Turn on the faucet.
Turn on all faucets in every level of the house. Flush all toilets, and turn off all toilet shut-off valves.
Attach a portable air compressor to the lowest faucet. Install an air fitting between the faucet and compressor hose. Close all faucets in the home. Turn off the water heater gas supply. Turn on the compressor, and apply 70 lbs. of pressure into the water pipes.
Turn on the hot water faucet to completely drain the water heater tank. Turn on the dishwasher for two minutes to rid the line of the last remnants of water. Run the washing machine on hot and cold, to rid the lines of water. Open the shut-off valves on all toilets to rid the final water from the lines.
Pour a thimble full of anti-freeze (non-toxic propylene glycol) into every sink and bathtub/shower, to ensure that the water in each P-trap doesn't freeze. Pour a cupful of anti-freeze into the all toilet tanks.
Attach the garden hose to the outlet on the bottom of the water heater tank and drain the water from the tank.