Position a heater near the frozen section. Never leave it unattended. Heat Lamps: These provide consistent, directed warmth.
If you suspect the freeze is deep in the main sewer line or if you see signs of a pipe already leaking/bursting, turn off your main water valve and call a plumber immediately. They have specialized equipment like "hydro-jetters" that use heated, pressurized water to clear deep ice blockages safely. how to unfreeze a drain line