I BELIEVE THAT YOU ARE TALKING ABOUT THE DRAIN LINE FOR YOUR T&P VALVE ON THE HOT WATER HEATER. IF SO YOUR NEED TO REPLACE IT. AFTER YOU REPLACE OT WATCH IT TO MAKE SURE THAT YOUR HEATER IS NOT CAUSEING THE PROMBLEM. MOST OF THE TIME IT JUST NEEDS A NEW T&P VALVE AND YOUR PROMBLEMS WILL END. YOUR FRIEND THE PIPEXPERT
