Never use an open flame (propane torch) on a drain pipe – it can melt plastic (PVC/ABS), start a fire, or generate toxic fumes. Use these safer methods:
If the frozen drain is in an unheated crawl space, place a radiant heater nearby (never inside a small sealed space without ventilation). Allow warm air to circulate for several hours. frozen drain pipe outside
Better yet, inspect your outside drains before winter: insulate, bury deeper, or install heat tape. A few hours of prevention can save you from a basement full of ice-cold sewage water. Never use an open flame (propane torch) on
If you currently have a frozen pipe, here is a review of the common methods to fix it: start a fire