If you leave your house before a freeze, turn off the water at the shutoff valve and leave your heat on.
Ideally, to protect from freeze damage, the water supply should be shut off and the pipes should be purged (drained) of water. If purging is not possible, at the very least, faucets should be left open. This will allow the water to expand as it freezes so it will be less likely to burst the pipes or damage faucets.
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.
Watering your plants before a freeze is a crucial step in protecting them from the harsh cold. When the temperature drops below freezing, it dehydrates the plant. Watering just before a freeze creates greater warmth in the soil, as the saturated soil will lose this heat slowly as the temperature drops.
Shutting off the water will not keep the pipes from freezing. The water in the pipes could still freeze and burst the pipe.
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.
In Which Seasons Should You Ensure That Your Water Supply Is Turned Off? Regardless of the season, you should ensure that your main water supply is turned off before leaving for vacation. However, in winter, you should be more vigilant. During this season, the water inside water pipes may freeze.
When the weather is very cold outside, let the cold water drip from the faucet served by exposed pipes. Running water through the pipe - even at a trickle - helps prevent pipes from freezing.
What Temperature Is Freezing? Water will freeze at 0 degrees Celsius, which is 32 degrees Fahrenheit.
There is a misconception that if water can be kept moving, it won't freeze. Wrong! Water freezes at 32°F (0°C). Period.
Frozen pipes can cause serious water damage to your home. The warm water your heater produces will continue circulating your system and prevent the leaks, cracks, and burst pipes that freezing can cause. Leave your water heater on to avoid frozen pipes and accompanying damage to your property.
Help avoid water damage by turning off your water supply
If a pipe bursts or leaks while you are away, it could cause significant damage. Consider completely turning off the water supply if you will be away for an extended period of time.
Does shutting off the water affect the water heater? When you go on vacation, it's best to also turn off your water heater, as well as the main water supply. Turning off the source of the heat (gas, electric) while you're away will not damage your water heater.
Yes, pipes can freeze overnight if temperatures plummet drastically. Uninsulated pipes in unheated areas like attics or exterior walls are most vulnerable.
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.
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.
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.
Pipes can freeze at temperatures below 32 degrees, but most insulated pipes start to freeze at temperatures below 20 degrees, according to Angi, a website that provides information on home improvement projects. If a cold snap lasts for more than four to six hours, your pipes could burst, according to Angi.
If you apply enough pressure (making it hard for the water molecules to spread out into the solid structure), you can have liquid water several degrees below zero degrees Celsius. Even if you don't apply pressure, you can still have liquid water at sub-zero temperatures using additives.
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.
Don't turn off your water, unless you're prepared to fully drain your pipes. Experts say there's a lot better and even cheaper ways to keep your pipes from bursting.
Your Pipes Could Freeze and Burst
If you turn off your water heater, your interior temperature will drop, leaving the water in your pipes susceptible to freezing. When the water in your pipes freezes, it expands and becomes ice. That ice creates blockages in your pipes and causes pressure to build.
Preventing Extensive Water Damage in Your Home
Shutting off the water is crucial for protecting your home from water damage through leaks or burst pipes. The last thing you want is to find the house flooded and with a foul smell when you return. Leakages can start from small drips along the length of the piping.
Shutting off the water supply when leaving for an extended period can prevent potential leaks or flooding while you're away.