Put a $9 heat gun on a frozen drain line in my own basement and it did nothing
My washer stopped draining and rather than pull the pump I figured the trap was iced up from the cold snap here in Rochester, so I hit it with a heat gun for about 15 minutes and got zero movement. Pulled the pump instead and the impeller was jammed with a sock. Lesson is I trust a theory over the part 9 times out of 10, anyone else do the same thing on their own stuff but never on a customer's?