Pipe-thawing options: There are several things you can do to thaw your home's pipes. Here's a list: Probably the most popular and safest pipe-thawing option is to use hot water.
Apply heat
Use a space heater, heat lamp or hair dryer to thaw the frozen length of pipe. Start looking for the frozen pipe by checking pipes along exterior walls, in basements, in crawl spaces, under sinks, in attics or any cold area of your home.
Be prepared to wait at least 30 to 60 minutes. When the pipe begins to thaw, water will start flowing at a faster rate through the open faucet. Even after the water pressure is fully restored, it's recommended to keep the heat on the pipe to ensure the ice in the line is completely melted.
Be sure to leave your faucet open on frozen lines to help relieve the pressure and hopefully prevent a burst pipe.
Probably the most popular and safest pipe-thawing option is to use hot water.
Pipes typically burst when exposed to extremely low temperatures for an extended period of time (anywhere from 1-3 days depending on temperature). This is especially true for pipes located on exterior walls. A frozen pipe is likely to burst when any water or liquid trapped within it freezes and begins to expand.
If you suspect that there are pipes in or above the garage, use space heaters to heat up that space as well. Make sure to keep heaters away from anything potentially flammable! Your pipes will eventually begin to thaw on their own once the temperatures rise above freezing.
Turn on all faucets: Checking each faucet in your home will help you narrow down your search. The faucets that have little or no water pressure likely have a frozen pipe in their supply line. If every faucet is showing low water pressure, the frozen pipe may be near the water meter.
Turn the Heat Upin the Property: You can attempt to thaw the frozen pipe by increasing the temperature in the property. Turning the thermostat up may be all that is needed to allow the ice blockage to melt.
Pipes: Turn off water supply to the house and drain pipes to protect them from freezing. You can empty pipes by running the water and flushing the toilets after the water has been turned off. After draining the pipes, it is a good idea to leave the faucets open to prevent pressure build up from any water that remains.
Tip #7: A Thaw Machine Will Be Your Savior
It's exactly what it sounds like: a portable device that plumbers use to thaw pipes quickly.
If you suspect that your outdoor faucet is frozen, there are a few ways to tell. First, check the temperature of the faucet; if it is cold to the touch, this could be a sign that it has frozen. Additionally, if water isn't coming out when you turn on the tap, this could also indicate freezing.
Prevent Frozen Pipes
Moving water keeps pipes from freezing. Find shut off valves for emergencies. Insulate pipes in unheated areas. Open cupboards and vanities to warm pipes.
No water or a slow trickle when a faucet is used. Whistling and banging coming from pipes, or strange bubbling sounds when you flush a toilet. Dampness, puddles, or rings on drywall or ceilings—signs of an urgent issue.
"It all depends on how fast the cooling occurs, and it turns out that hot water will not freeze before cold water but will freeze before lukewarm water.
Keep the faucet open. As you treat the frozen pipe and the frozen area begins to melt, water will begin to flow through the frozen area. Running water through the pipe will help melt ice in the pipe.
Manually thaw: Begin the thawing process at the most vulnerable places (near faucets). By targeting these areas first, your pipes will be less likely to burst. To do so, gently apply heat to the frozen areas. A blow dryer is a good option (use caution, go slowly, and don't use an open flame).
It's important to note that you shouldn't fully open your faucets and plumbing fixtures directly after a freeze. This will drastically increase the water pressure within the pipes if there is any frozen water inside them, causing the pipes to burst.
Frozen Pipes Shouldn't Be Allowed to Thaw on Their Own
The laws of physics say water always takes up more volume as it freezes. When your pipes can no longer contain the expanding ice, they will burst. This not only breaks the pipes and makes your plumbing system unusable, it may cause serious water damage as well.
If a pipe freezes
Turn off the stop valve immediately and open all COLD taps to drain the system, but NEVER turn on the hot taps – if you have a hot water cylinder it may collapse if the pipes leading to it are frozen.
However, both PVC and CPVC (think of them as coming from the same family of plastic pipes) are brittle and will crack at low temperatures. So, while not the worse solution, they are still vulnerable to freezing conditions.