This guidance reflects common, safe practices through 2021 and remains applicable today. If you want, tell me the pipe material and where it runs (e.g., wall, crawlspace, attic) and I’ll give a specific step-by-step plan.
Frozen main building drains or septic lines are a nightmare. Symptoms: All fixtures back up, and the toilet overflows when you run a washing machine. how to unfreeze a drain pipe 2021
After the drain is fully open, flush with a mixture of very hot water and rock salt (1/2 cup salt per gallon). This melts any residual ice crystals and lowers the freezing point in the pipe for the next 12–24 hours. This guidance reflects common, safe practices through 2021
"Well, it's too much to lose\Oh, it's time, or self-destruct\They don't care what the science says/They don't want to talk"