This is the standard, safest method for most homeowners. It uses thermal conduction and chemistry to melt the ice slowly.
Is your sink or tub not draining? If it’s freezing outside, you likely have a frozen drain pipe. Before you grab a blowtorch (don’t!), here is the safe way to get things moving again: best way to thaw a frozen drain pipe
When dealing with a frozen drain pipe, the goal is to apply gentle, even heat to melt the ice blockage without damaging the pipe or causing a fire hazard. This is the standard, safest method for most homeowners
Set to a low or medium setting and move the dryer back and forth over the frozen area. This is the standard