Five Reasons a Water Heater Can LeakFix

Hot water heater
Monty Rakusen / Getty Images

Fixing a leaking water heater can range from the very easy to the very challenging. At the first sign of leaking, many people leap to the conclusion that the water heater must be replaced, but that's not always (or even usually) necessary. Many potential fixes are actually rather simple and inexpensive, and sometimes replacing a broken part can extend the life of the water heater for several years. Here are some basic steps on how to check where the leak is coming from and possible ways to...MORE fix it.

  • 01 of 05

    Leaking at the Water Supply Lines

    Insulated water heater flex lines
    Aaron Stickley

    The first place to check is the plumbing pipes above the water heater. A drip from above can easily leak down on top of the water heater and even work its way down the insulation and make it look like a leak coming from inside the tank. This is why it is important to always look above the water heater first.

    Get a ladder if you need to and check the plumbing above the water heater. Pay special attention to the water supply lines going into the water heater. Flexible water supply tubes are the...MORE most common cause of leaks above the water heater, as it is common for the tubes to fail long before the water heater is ready for replacement.

    If there is insulation around the supply tubes above the water heater, remove them so you can inspect and replace them if necessary. To replace the water heater flex lines, first shut the water off. Before removing the water supply tubes, verify that the hot water is turned off by turning on the hot side of a faucet in the house to see if hot water continues to flow.

  • 02 of 05

    Leaking at the Water Heater Nipples

    Water heater nipples
    Aaron Stickley

    The water heater nipples on top of the water heater can be another common place to find a leak. The threads are the thinnest part on the nipple and it is not unusual to find leaks in them. This can be hard to differentiate from a leak at the supply tube but if you changed the supply tube already and it is still leaking, the nipples are a likely cause. Removing the water heater nipples can be quite difficult and will require a pipe wrench and some leverage. Make sure shut off the hot water and...MORE double check it before doing this repair is.

  • 03 of 05

    Leaking at the Temperature and Pressure Relief (T-and-P) Valve

    Water heater Temperature and Pressure relief valve
    Aaron Stickley

    Another possible place for leaks is the temperature and pressure ( T and P) valve. A leak at the T and P valve is a more serious situation and you will want to take the time to figure out the cause. A T-and-P valve will not usually begin dripping or leaking unless there is a problem. 

    • If the valve was removed recently, it's possible it is now failing to seal properly. Tightening the valve, or reinstalling it with Teflon tape on the threads may solve the problem.

    • If the water heater is...MORE heating the water too much, the excessive pressure may be causing the T-and-P to leak.The solution might be to lower the water temperature or to install a water expansion tank if you don't already have one in your plumbing system. 

    • The leaking T-and-P valve may indicate the overall water pressure in your home is too high, and that the pressure regulator is not working properly. 

    • But if the water pressure in the house seems normal and the water heater is heating normally, then you may have a faulty T-and-P valve that needs replacing. When replacing the valve, make sure the hot water is off and the pressure is off of the line before making the repair.

    If you believe there is still a problem or are unable to get to the bottom of the issue, call a professional plumber to help assess the situation.

  • 04 of 05

    Leaking at the Drain Line

    Water heater drain valve
    Aaron Stickley

    A leak in the drain valve at the bottom of the water heater is a common issue. After draining or flushing a water heater, it is common for the drain valve to fail to close completely. This drain valve can be capped with a hose cap, or you can replace the drain valve completely with a new and improved valve. You will have to shut off the hot water and drain down the water heater to remove the valve.

    Continue to 5 of 5 below.
  • 05 of 05

    Leak in the Tank

    Water heater leaking at the tank
    Aaron Stickley

    In none of the prior inspections showed a cause for leaking, then most likely the tank inside the water heater has gone bad. If the tank is leaking, it cannot be fixed and you will have to replace the water heater.