When the mercury hits the freezing mark of 32 degrees, it’s time to turn on faucets in the home, a Wilmington-area plumber advises.
“Once it drops down to freezing, turn the tap on. Just leave a faucet dripping,” said Donald Barnhouse, owner of DB Plumbing in Leland, which serves New Hanover, Brunswick and Pender counties.
Only in extreme cold conditions atypical in Wilmington will pipes freeze if a faucet is left dripping, Barnhouse said.
“That’s what I do when it drops below 32 degrees. I turn a faucet on and I let it drip,” Barnhouse said.
State Farm Insurance says about 250,000 families across the U.S. experience burst water pipes every year.
“When the outside temperature drops below freezing, water pipes in homes with little or no insulation are likely to freeze and break. A 1/8th-inch
crack in a pipe can spew out more than 250 gallons of water a day,” according to the State Farm website.
The website offers the following tips to prevent frozen pipes:
Disconnect outside garden hoses
Open cabinet doors to allow heat to get to piping under sinks and vanities near exterior walls
Run a small trickle of water at vulnerable cold and hot faucets.
If you suspect water pipes have frozen, turn off the water at the main shut-off valve. Make sure that everyone in the family knows where the water shut-off valve is and how to open and close it, State Farm advises.
Related links:
What were the warmest and coldest winters on record for Wilmington?
What is the coldest low temperature and coldest high temperature recorded in Wilmington’s history?
Date posted: December 14, 2010
User-contributed question by:
Nancy Bair

The Weather Channel has a page on this topic, including research done at the University of Illinois. They’re recommended threshold is 20° ambient.
http://www.weather.com/activities/homeandgarden/home/hometips/severeweather/pipefreeze_prevent.html
32F is waaaaaay to warm to worry about frozen pipes.
Ask a plumber from a northern state for an accurate answer.