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Fix A Leaking Water Heater


Fixing a leaking water heater can range from easy to impossible. Most people think the only solution for a leaking water heater is to replace it the entire unit. That might not be necessary. There are many things on and attached to the water heater that could make it look like the tank is bad when it is not. Replacing the broken part will fix the leak and could extend the life of the water heater several years. Here are some basic steps on how to check where the leak is coming from and how to fix it if possible.

1. Leaking At The Flex Lines

Insulated water heater flex lines
Aaron Stickley
The first place to check is the plumbing 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 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 flex lines going into the water heater. The water flex lines are the cause of most leaks above the water heater. The water flexes can go bad and leak well before a water heater is ready to be replaced. If there is insulation around the water flex lines above the water heater, remove them so you can inspect and replace them if necessary. To replace the water heater flex lines first thing to do is to shut the water off. Before removing the flex lines verify that the hot water is turned off by turning on the hot side of a faucet in the house.

2. Leaking At Water Heater Nipples

Water heater nipples
Aaron Stickley
The water heater nipple 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 a leak in them. This can be hard to differentiate from a leak at the flex line but if you changed the flex line 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 double check it before doing this repair.

3. Leaking At The Relief Line

Water heater Temperature and Pressure relief valve
Aaron Stickley
The next thing to check 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. It could be that the valve was pulled to let some air into the tank to help drain it and now it will not seal (common). A T and P valve will not usually go off on its own and start dripping or leaking unless there is a problem. Either the water heater is heating the water too much or with the added heat there is too much pressure building up. Check the water pressure at your house because having the T and P line going off could be the first sign that the pressure regulator on the house is not working correctly. If the water pressure in house seems normal and the water heater is heating normally then you may need to replace the T and P valve. 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 you are unable to get to the bottom of the issue it is a good idea to call a professional plumber to help assess the situation.

4. 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 a old valve to not shut back off completely. This drain valve can be capped with a hose cap or the better way is to 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.

5. Leak In The Tank

Water heater leaking at the tank
Aaron Stickley
If you checked the water heater for all the other types of leaks and found them lacking then most likely the tank inside the water heater is bad. If the tank is leaking it cannot be fixed and you will have to replace the water heater.
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