Your Old Hot Water Heater Is Probably Leaking

Your Old Hot Water Heater Is Probably Leaking
Photo: Karen Hermann, Shutterstock

Hot water heaters are one of those household appliances that you tend to forget about until something goes wrong. It’s easy to let years — maybe even a decade or two — pass without paying much attention to it. But if you have a traditional hot water heater (not one of the newer tankless models) and it’s getting up there in age, don’t be surprised if/when it starts leaking.

There are a few reasons why water may be dripping (or trickling) out of your water heater. Here’s how to identify where the leak is coming from, and what to do next.

How long do hot water heaters last?

Part of the appeal of tankless water heaters is that they typically last at least 20 years. Traditional tank-type hot water heaters, on the other hand, generally last between eight and 12 years — depending on how they’re maintained and the mineral content in the local water supply.

Why is my hot water heater leaking?

Here are the three most common causes of leaking hot water heaters, and how to (potentially) fix them:

The drain valve

If water is leaking from the bottom of your hot water tank, check the drain valve first. It’s located on the bottom of the appliance and looks like a spigot you’d hook your hose up to outside. You should be able to tell by looking at the area around the valve whether it’s responsible for the leak. You can double check by wiping a cotton swab or something similar inside the opening of the valve to see if it’s wet.

The fix: If the drain valve appears to be the source of the leak, first check to see whether the knob or handle is closed tightly. If it’s not, that could be causing the leak.

The drain valve could also be faulty and need to be replaced. Unless you know what you’re doing, that’s a job for professionals.

The temperature and pressure relief valve

The temperature and pressure relief valve (usually referred to as the “T & P valve”) is a safety feature that releases excess pressure from the tank. The valve itself is usually located on the top or side of the water heater with a thin pipe (either metal or plastic) attached, pointing down to the ground. Check to see whether it looks like the leak is coming from that pipe, and again, use a cotton swab to determine whether the inside of the pipe is wet.

The fix: T&P valves aren’t something to play around with, so if it appears to be the source of your leak, call a professional to assess the situation. They can replace the valve and/or pipe, if necessary.

The internal tank

Unfortunately, the appliance’s internal tank is the most common source of leaks — especially as the water heater gets up there in age.

Technically, homeowners are supposed to flush their hot water heater at least once a year to remove any built-up mineral deposits and sediment that have accumulated in the tank. When this isn’t done for long periods of time (or ever), the sediment that settles in the bottom of the tank can corrode or crack the tank shell, causing it to leak.

If you’re able to safely remove the front panel from your water heater, shine a flashlight inside and look for evidence of corrosion, like rust or moisture. You may even see the leak itself.

The fix: If it’s very clear that your internal tank is responsible for the leak, start calling around for estimates: You’re going to need a new one. If you’re not able to open the front panel, or are still unsure about the source of the leak, call a professional for an assessment. They’ll let you know whether your water heater can be fixed, or if you need a replacement.

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