Unlike pressurized water supply lines, drain pipes are not always full of water. They freeze when water sits stagnant in a low spot or when the pipe has a shallow slope. Common culprits include:
: For partial blockages, run a garden hose from a hot water heater to the drain access point. Use a small pump to force the warm water against the ice blockage until it breaks. Professional & Advanced Methods how to unfreeze a drain pipe 2021
For drains that are only partially frozen or sluggish, a little chemical reaction can go a long way. Unlike pressurized water supply lines, drain pipes are