Hello, this week, despite constant heating, the sewage line in the trailer was frozen. A parallel mix of 2 solutions was helpful. Which of these was the decisive component?? I don’t know … but it worked. 1.) A good load of salt dissolved in warm water in the drain 2.) Two bit cleaner tabs shredded afterwards, so that “movement” comes into the matter The bit cleaner tabs I always have in the trailer for tank cleaning anyway. all of a case just try it out. Can’t hurt at least nothing GreetingNoGolf