To clear a frozen tub drain, locate the frozen pipe, open the faucet, insulate the pipe, heat it with a hair dryer, warm it with a space heater, and test the pipe. This project takes several hours and requires towels, hot water, a hair dryer and a space heater.
- Locate the frozen pipe
Isolate the frozen pipe by feeling the household waste lines with your hands.
- Open the faucet
Turn off the water supply, and open the bathtub faucet. Leave it open while you thaw the drain pipe.
- Insulate the pipe
Submerge towels in hot water, wring them out, and wrap them around the end of the frozen pipe closest to the bathtub faucet.
- Apply hot air
Blast the pipe with a hair dryer on the hottest setting. Move the dryer back and forth along the pipe, starting near the faucet. Slowly work down the pipe in sections, reheating and repositioning the towels as necessary.
- Melt residual ice with a space heater
Remove the towels, and set a space heater close to the pipe. It must be at least 8 inches away from the pipe, walls and all flammable surfaces. Turn on the heater, and leave it near the pipe for several hours.
- Test the pipe
Turn on the household water supply, and inspect the bathtub. If it is draining properly, close the faucet, and remove the space heater. If the drain is slow, leave the heater on for several more hours, and then test the pipe again.