Water heater failures come in a few categories, but leaks can be some of the most frustrating and damaging. A leaking water heater might make a small puddle or produce a large flood that can damage your basement and ruin nearby equipment. Since water heater tanks can contain a lot of water, shutting off the supply won't always immediately solve the problem.
Once you spot a leak, you'll need to take some steps to minimize the damage and diagnose the problem. While repairing the issue will usually require the help of a plumber, that doesn't mean you can't do a little diagnostic work before they arrive. These three tips will help you assess your problem and determine if you need to make an emergency plumbing call.
1. Look for Active Leaking
There are numerous locations where leaks can form on a typical water heater, including the temperature and pressure (T&P) relief valve, supply and outlet lines, and drain valve. Electric water heaters can also leak near the heating elements if the gaskets wear out or break. In a worst-case scenario, the tank can rust and leak.
If you see water on the floor near your water heater, look for active leaks from any of these locations. You may not be able to spot a small leak, but large amounts of water dripping or running on the floor likely indicate a serious problem. When you spot large leaks, turn off the heater, shut off the water supply to prevent the tank from filling more, and call a plumber for help.
2. Close the Drain Valve
Water heaters contain a drain valve to empty the tank for maintenance and to allow you to flush away sentiment periodically. Since this valve sees frequent usage, it's a common and relatively minor failure point. It's also easy to leave this valve slightly open after performing a water heater flush or other maintenance on the tank.
If you see a small amount of water near the tank's base, try tightening this valve and watching for additional leaks. You may have to check back a few times later in the day for small leaks. If the leak continues, the drain valve may be faulty, or the leak may originate from another nearby location. In either case, a plumber can help you locate the underlying issue.
3. Check the T&P Valve
The T&P valve is a critical safety feature that prevents the pressure in your water heater from increasing to dangerous levels. When the temperature inside the tank is too high, the T&P valve will allow some water to escape to bring the pressure back in line. Most modern heaters will have a discharge line (a long pipe) extending from the T&P valve to the floor.
Look for signs of dripping or pooling below the T&P line, but be careful since the water dripping from the pipe may be very hot. Leaking from this pipe may indicate a problem with the T&P valve, or it could be a sign of a more serious issue with your heating system. While addressing these leaks isn't necessarily an emergency, you should have a plumber investigate as soon as possible.
Contact a plumber for help with water heater repair.