When you can't cut a pipe, re-heat the solder Cutting a soldered pipe is always the best way to disconnect it. However, sometimes you cant. Either you would leave the pipe too short to make a new connection, or you just can't angle a cutting tool into the space. In these situations, the best solution is to pull off the fitting as the solder melts from your torch. Just have a wet rag handy, and be sure to quickly wipe away the molten solder before it hardens on you.

Use plastic drain lines instead of metal Plastic drain lines look a lot less reliable than metal ones, but this is not the case at all. Plastic is cheaper and easier to install, it is also easier to tighten and adjust if a leak every develops. Unlike metal, plastic is not corrosive. If your metal drain lines start to leak, the smartest move is to replace with plastic.

Do not re-use supply lines It is tempting when replacing a faucet or toilet to save a few dollars by reusing the flexible old supply lines, but just dont. These are made with thin flexible plastic, and even the smallest leak can lead to massive water damage. Sure the risk is small, but the cost can be significant if a leak does occur. Ask your plumber to replace these with new lines, encased in braided stainless steel. They are much less likely to leak and even if your old lines are braided steel, replace them as the cost is low and well worth the small investment for peace of mind.