Do you need to be concerned if you discover water leaking from your water heater's discharge pipe? What should you be concerned about if a pool of water unexpectedly appears near your hot water heater? Something is definitely wrong with your hot water heater's overflow pipe. Without knowing what it is, you have just discovered something called a T&PR valve, the most likely source of the problem.

Water heaters are simple appliances with just three connecting lines. There will be a cold-water inlet line, a hot water outlet line and then a third line attached to a brass valve with a small lever attached to it. That's the T&PR valve, the source of your water leak, but probably not your problem. Why? The purpose of the T&PR is to release hot water that has reached unsafe temperature and pressure levels.

This safety device protects the home from a dangerous situation where overheated water could result in an explosion. The valve is located either on the top or the side of the water heater. It will releases water into a pipe that is directed downward toward the floor or a drain below. It's a good idea to have the discharge line attached to a drain line or directly into a drain. While they are not truly overflow pipes, they do permit water to escape from the tank if the thermostat has failed.

At a preset level of pressure, the valve will open enough to vent the hot water to the outside of the tank. You may learn a tag attached to your heater's valve that will inform you how it operates. You can see the valves operational settings by examining the tag. Typically set for 120 degrees F, or a pressure of 150 PSI.

When the valve works as designed, it will detect the high water temperature and pressure, opening just enough to cause a puddle of hot water on the floor. It doesn't have to open very much to work properly, but the fact that it opened at all means something is wrong with the water temperature. Be careful around the discharged water, it will be hot. Next, consider calling a plumber to further troubleshoot the problem or do so yourself.

Performing a yearly check of the T&PR valve for corrosion and proper operation is a good idea. An operational check isn't difficult, but it does require that you exercise caution. Just one test is needed, lifting the lever attached to the valve will release some hot water from the tank. This will open the valve enough to allow hot water to flow through the discharge pipe. Once you let go of the lever, the water should stop flowing. This is a simple once-a-year check of the valve's working.

Unless tested at least once a year, T&P valves may become corroded and fail to operate properly due to presence of certain chemicals in the water. If the valve appears to be malfunctioning, you can call a plumber or replace it yourself. Generally, you should have a qualified technician or a licensed plumber replace a malfunctioning T&PR valve. It is important to replace the valve with a matching model and type that conform to the water heater's design specifications.

Hopefully, this article has given you some valuable instruction about what to do when water is leaking from your water heater's discharge pipe.