While your pipes are typically safe from freezing until temperatures get closer to 20℉ and remain at those levels for 6+ hours, your garden hose can start to freeze in as little as 6 hours once it gets below freezing temperature outside (32℉).
Most direct answer: As soon as the low temps hit freezing. Anything above freezing will not hurt you. But the lows may go to 20 degrees and the highs to 34. That's low enough to burst some pipes, crack valves, etc.
Your pipes are at risk of freezing any time temperatures drop below 32°F. However, it's much more common for pipes to freeze when temperatures dip below 20°F. The longer the weather remains below freezing, the more likely it is your pipes can freeze if not properly protected and winterized.
Water should be turned off before the temperatures drop below freezing. This is especially true if you will not be home during the winter and the heat will be turned off as well. Water that is left in the pipes will lose any warmth it has and begin to expand as it freezes.
Remember to disconnect garden hoses from outside water spigots when the temperature is going to drop below freezing. Hoses left attached don't allow water to drain properly. The water left in the spigot can freeze causing the pipe to break inside the wall.
While your pipes are typically safe from freezing until temperatures get closer to 20℉ and remain at those levels for 6+ hours, your garden hose can start to freeze in as little as 6 hours once it gets below freezing temperature outside (32℉).
As soon as the temperature drops to 32℉ for more than six hours, it freezes the water in the expandable garden hose.
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.
Water will freeze at 0 degrees Celsius, which is 32 degrees Fahrenheit. Any time the temperature drops below these, liquid water will begin to turn into ice. Water behaves very differently than other liquids. When liquid water freezes, the molecules spread out, making ice less dense than liquid water.
Yes, pipes can freeze overnight if temperatures plummet drastically. Uninsulated pipes in unheated areas like attics or exterior walls are most vulnerable.
So, exactly how cold does it need to be before you do this? Southern Living says professionals list the threshold temperature for pipes to freeze at 20 degrees Fahrenheit, meaning this or anything below can create a potential for water to turn to ice in your pipes.
The U.S. government Department of Energy (DOE) states that people should set their thermostats to 68 degrees F. This is the optimal temperature for keeping a home comfortable.
DURING freezing weather:
Open cupboard doors under sinks, especially where plumbing is in an outside wall, to allow interior heat to warm the pipes. If you plan to be away from home for several days, shutting off the water can reduce the chances of broken pipes. Set your home heat to at least 55 degrees.
Here's a list of ways to prevent freezing pipes in your home: Keep the thermostat at a minimum of 68 degrees Fahrenheit. Make sure pipes are properly insulated. Keep water slowly flowing on outer wall faucets.
Caulk and weather-strip doors and windows. Insulate walls and attic. Install storm or thermal-pane windows or cover windows with plastic from the inside. Repair roof leaks and cut away tree branches that could fall on your home or other structure during a storm.
What Temperature Will Cause My Pipes to Freeze? Pipes run the risk of freezing at temperatures below 32 degrees Fahrenheit, especially if they're not insulated, but most insulated pipes start to freeze at 20 degrees Fahrenheit or below.
As you winterize, it's very important to remember to disconnect the hose for winter. A hose connected to an outside faucet is exposed to the elements. The water inside the hose can rapidly freeze when the temperature drops below 32 degrees.
At what temperature will PEX freeze and burst? PEX pipes are extremely burst- and freeze-resistant because of their insulation properties and natural flexibility. However, at certain temperatures, even PEX can no longer stand up to the elements. The temperature cutoff for PEX pipes is around -7°C.
Overall, it's best that you take heed and drip your faucets when temperatures dip below freezing. A simple trickle of hot and/or cold water—both from faucets inside and outside the home—can prevent you from having to deal with a much larger issue (and bill!) in the long run.
When temperatures plummet, the risk of your pipes freezing and bursting skyrockets—a reality that may end up costing you a lot of time and money. In fact, burst pipes are one of the most common causes of property damage during frigid weather.
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.
Water expands when it freezes, so it's important to remember to detach your garden hoses at the end of the season. Even if you have a “frost-free” spigot, you still need to remove the hose in the winter or run the risk of your pipes freezing and bursting.
If the hose is in good condition, then nothing happens. The hose remains pressurized by the water pressure, and that's it. If the hose is in poor condition it is possible that it can burst from holding that much pressure for that amount of time.