For metal traps only (salt corrodes some metals). Mix 1 cup salt with 1 gallon warm water. Pour slowly. Salt lowers freezing point. For Drains Inside Walls (No Direct Access) A. Increase room temperature Open cabinet doors under sink to let warm air circulate. Use space heater in the room. Raise thermostat to 75–80°F for a few hours.
Attaches to metal drain lines, sends current through pipe to warm it. Not for PVC/ABS. Risk of igniting sewer gas — ventilate area first. how to thaw a frozen drain
Hold 6–12 inches away, keep moving. Works well on metal pipes. On PVC, keep temp below 140°F (60°C) — if the pipe gets too hot to touch, stop. For metal traps only (salt corrodes some metals)
Aim at the wall where you suspect the freeze. Check for hot spots; don’t overheat drywall. Salt lowers freezing point