Left unattended, the frozen water can continue to expand until it bursts the supply pipe leading to the spigot itself. When the ice inside the supply pipe thaws, the melting water inside the pipe escapes through the rupture and can flood your home. You can have a nasty surprise and a mess to clean up.
When the outdoor temperature drops, any water inside the spigot or connected pipes can freeze and expand, which can cause cracks or bursts in the plumbing. During winter months, when spigots are left uninsulated, or when water is left in the spigot or pipes, it can contribute to a frozen outdoor spigot.
Yes, you should leave the faucet open just a bit to allow for expansion of the water if you can't get it thawed... If you know where it is frozen, you can put a hair dryer on the line to slowly thaw it... You don't want a fast thaw as that can also cause expansion that can burst the pipe...
Even if they're frost free you should shut the water off and open them outside to keep them from freezing.
Your pipes will eventually begin to thaw on their own once the temperatures rise above freezing.
Apply heat until full water pressure is restored. If you are unable to locate the frozen area, if the frozen area is not accessible, or if you can not thaw the pipe, call a licensed plumber.
An increase in indoor temperatures can help unfreeze all your indoor pipes, whereas your outdoor pipes may take longer. In many cases though, using the right heating tools can unfreeze your pipes in a matter of 30-45 minutes.
With this in mind, expect most pipes to freeze within six to eight hours. Uninsulated exterior pipes can freeze in under six hours if the temperature is below 20 degrees. It takes at least 12 hours for unprotected pipes to freeze at 32 degrees.
Thaw Frozen Pipes
Turn off the water immediately at the main shut off valve. Open the faucet so that water will flow through the pipe once the area is melted. This will help melt more ice. Apply heat to or around the pipe using a hair dryer.
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.
And if you're a little too late, and your garden tap has already frozen over? Don't panic: this doesn't mean that it's already caused a burst pipe or broken valve. Try wrapping it in a towel that's soaked in hot water, or pour warm water over it to unfreeze it.
The core mechanism that sets frost-free hose bibs apart is their elongated stem or shaft, which extends from the outdoor spigot into the interior of the home, where temperatures remain above freezing.
A freeze-proof faucet protects your outdoor spigot from freezing and bursting. The design slopes downward toward the spout to drain water. An interior shut-off valve also protects water from building up and freezing in the pipe. These faucets are also called frost-proof faucets, spigots, or hose bibs.
If that pipe is made of copper or plastic, it often splits open the pipe. As long as the pipe remains frozen, you won't notice the problem, but after it thaws, the pipe can flood your home. Very quickly.
If you do not want to spend extra money on a high water bill, or you are able to isolate your exterior faucet from the mains water supply, then covering the faucet will likely be better for you. If you can drip your faucet, however, then it may be more effective in protecting your pipework from over-expansion.
A foul smell from the drain or faucet is a less-obvious warning sign. Odors are unable to filter out of the frozen pipe and instead are forced back into the home's faucet. 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.
Essentially, anything left attached, even if the outdoor faucet is in the shut position, can prevent the outdoor faucet from draining. If the outdoor faucet doesn't drain, then the remaining water can freeze.
Apply heat to the frozen area
Slowly apply heat using a hair dryer. There are several ways to do this. You can wrap the pipes in thermostatically controlled heat tape, or you can use an external heat source such as a hair dryer or space heater.
Ask any plumber, "Should I turn off the water if pipes are frozen?" and they'll immediately tell you, "Yes." Locate your main water line and switch the shut-off valve so the flow of water stops. By doing this, you'll reduce the amount of pressure that builds inside your frozen pipes.
The job goes more quickly by pouring hot water or a mixture of vinegar, baking soda and salt water down the drain. Space heaters, hair dryers and heating pads are highly efficient tools for unfreezing a drain pipe. If a frozen drain line ruptures, turn off your home's main water supply.
Technically yes, but the “wait-and-watch” method carries risk. As that ice begins to thaw, any water caught between the faucet and the ice will cause increased pressure within the pipe. That increase in pressure can lead to frozen pipes bursting.