To fix a frozen main water pipe, first shut off the main water supply valve to prevent damage from expanding ice. Insulate the pipe with foam boards or heat tape, focusing on sections exposed to cold air. Apply consistent heat from a hairdryer or heat gun to gradually thaw the pipe, avoiding direct contact to prevent burns. If the pipe is already burst, immediately turn off the water, drain the system, and contact a licensed plumber. For prevention, insulate pipes 5-10 feet from the ground and seal gaps around windows and doors.

Pipe freezing typically occurs when temperatures drop below 20°F (-6°C), causing water to expand and crack pipes. The Insurance Institute for Highway Safety reports that pipe bursts account for an average of $5,000 in property damage per incident, with 65% of failures occurring in homes with poor insulation. The Environmental Protection Agency (EPA) emphasizes that insulating pipes reduces burst risks by 80%, as ice expansion creates 30 times more pressure than standard water flow. Data from the National Weather Service shows that prolonged exposure to sub-20°F temperatures increases burst likelihood by 40%, particularly in unheated basements or crawl spaces. Regular maintenance, such as annual inspections and applying glycol-based antifreeze, can further mitigate risks. A 2021 study by the American Water Works Association found that homes with insulated pipes experienced 70% fewer plumbing emergencies during extreme cold. Proactive measures not only prevent costly repairs but also extend pipe lifespan by up to 15 years.