Diagnosing a Plumbing or Drain Problem

Some plumbing problems are easy to diagnose, but many times they are quite difficult. If a drain is clogged, you have to determine where the blockage is in order to clear it. Leaks, on the other hand, can be much harder to diagnose.  Leaks can come from the water supply or from drains. Sometimes a leak can just be the symptom of a blocked line. That is why it is important to correctly diagnose it.

Water comes in through the water supply lines, generally 1/2″ and 3/4″ in a residence. These pipes are usually copper or plastic, called PEX. Supply lines can either leak or burst. The most common causes for this are pipe freezing or pipe corrosion. Once the leak is found, that section of pipe should be replaced. Faucets and toilets can leak, in which case they need to be rebuilt. A toilet is easily repaired, while nowadays it is often cheaper and wiser to simply replace an entire faucet.

Drain lines are made out of PVC, Cast Iron Pipe, Vitrified Clay Pipe (or Terracotta), Galvanized Steel and in very rare cases, Orangeburg Pipe. PVC is the newest and most reliable. It can dip in the ground. Clay Pipe allows roots to grow into it. Cast Iron and Galvanized Steel can corrode. Orangeburg Pipe is made from tar paper and hasn’t been used in decades.


Steps to Diagnosing a Problem


Water Supply Problem

  • If there is a leak, turn off all of your fixtures and look at the water meter. If the red triangle is spinning, there is a leak in the supply line. This can also find leaking toilets.
  • A running toilet could just need an adjustment to handle chain or float adjuster. If this doesn’t work, the ‘guts’ of the tank need to be replaced.
  • Loss of water pressure could be caused by minerals or debris in the line, partially closed valve, pressure reducer, or could be a leak or broken line. Try removing the faucet aerator from the faucet to see if this is the problem. Make sure to replace it.
  • If you don’t have hot water, it could be that the pilot is out or a breaker blew. Other problems are more difficult to determine.

Drain Problems

  • If you have a blockage in one drain, run water in other drains to see if they back up. This determines whether the blockage is local or further down the line.
  • If a toilet is blocked, but nothing else is, you can often fix the problem with a plunger.
  • If a floor drain backs up, the blockage is in the main line.
  • A slow drain could either be a partial blockage or a venting issue.