Here are some steps to help you keep water flowing in cold weather. From http://www.wikihow.com/Prevent-Frozen-Water-Pipes
Insulate all water pipes from cold moving air and keep them dry. Locate the main water shut off in case you need it. Leaks often happen if the pipe is thawed out.Ad
Use either heater tapes wrapped around the pipes or a heated reflector lamp in a dry enclosed space. On cold nights, check the light to see that it is working. The heater tapes work by a built-in thermostat. In order to work, the tape must be wrapped between the pipe and the insulation.
If electric power is unavailable or is lost, let the water run no faster than a slow constant drip; this is cheaper than repairing it. First start a slow drip on the hot side faucet, then a faster drip on the cold side faucet. There is no need to run a lot of water. Bathrooms can be cold, as long as they aren’t freezing.
Remember to insulate and heat the drain lines in crawl spaces and cold basements. Again, a heat lamp focused on the drain p-trap will keep it from freezing if it is also protected from moving cold air with a boxed enclosure that you can build yourself.
To thaw a frozen pipe, first check the pipe in the area of the freeze. Some plastic or copper pipes will split and will flood the area when thawed. If the pipe looks busted or has a slit in it, call a plumber. If the pipe is all metal, it can be thawed by connecting a welder onto the pipe on each side of the frozen part. After a while it will be running again. This is just like connecting starter cables to the car battery, but with much longer cables.
It is far better to heat the area around the frozen part with an electric space heater, a hand-held hair dryer, or a heat lamp in a reflector to prevent a fire. If this is a problem, call the plumber. Some of them don’t mind if you watch them as long as you are quiet and not in the way.
Always disconnect your water hose from your outdoor spigot in the winter, or before the temperature in your area drops below freezing. The water inside the hose can freeze, and the freezing continues back into the spigot until it reaches your pipes. If you have PVC plastic piping leading to this spigot, it will burst.
Use a temperature-controlled thermal convection powered hot water recirculation valve (which does not require electricity to operate) to continuously circulate warm water throughout your hot and cold waterlines anytime the temperature is below the user chosen set point 77F-140F. Unlike heat tape which only heats the pipes, this process circulates water non-stop to prevent crystallization and freezing no matter where the pipes are hidden. Note: This method requires that the valve be installed at a higher level (2nd – 3rd floor) than the water heater. Circulating water throughout your system non-stop will also increase your water heating bill.
Use a product called ICE LOC which prevents pipes from rupturing by taking up the expansion of the frozen water. It’s an elastomer that fits inside pipes that are in trouble areas.
Use a RedyTemp, a device which utilizes an internal water contacting temperature probe to monitor the temperature of the water inside the pipes. Depending on the temperature set point you choose on the unit’s temperature dial, it will circulate as needed to maintain the selected temperature. The RedyTemp optimizer installation is a DIY project and takes twenty minutes to install under a sink. Disconnect one end of the existing faucet supply lines and connect to the RedyTemp. Connect the two faucet supply lines which come with the RedyTemp. Plug the unit into a standard wall socket and set the desired temperature set point. Users can gauge the effectiveness of their chosen set point by opening a cold water faucet and feeling how cool/ambient/warm the water is it comes out of the tap, and adjust the set point until optimized.