A small leak is found on a soldered joint on an internal cold water supply pipe, what action should be taken

• A. Drain the system down and resolder fitting
• B. Tighten the joint
• C. Insulate the pipe
• D. Isolate and replace the pipe

Answer: (A)

When a leak appears at a soldered joint on a cold-water line, the right repair is to depressurize the system and re-solder the joint. A leak at a soldered connection usually means the bond hasn’t formed properly or has degraded, so simply tightening won’t stop the water because there isn’t a threaded fit to tighten. Draining the system removes pressure and moisture, giving you a clean, dry surface to rework the joint and ensure a proper solder fillet.

After isolating the supply, you’d dry and clean the joint, remove old solder if needed, apply flux, and then reheat and feed in fresh solder to form a solid seal. Once it cools, re-pressurize and check for leaks. Insulating the pipe won’t stop the water flow, and replacing the entire pipe is more invasive and unnecessary if the joint can be remade properly.

If the pipe or joint is badly corroded or damaged, replacement might be required, but for a small leak at a soldered joint, draining and re-soldering restores the proper seal.