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Why Is My Water Heater Leaking? Most Common Reasons Explained

Many people frantically google “why is my water heater leaking” when it’s already too late to fix it on their own. In this article, we have explained what may be going on with your water heater.

Is your water heater leaking? A leak in the water heater can not only waste hot water and energy but can also generate a whole host of other moisture-related issues. So, if you observe the water heater leaking from the bottom, be sure to investigate further while the Smart Air Cooling and Heating team comes over to your location. You need immediate help from a reliable local heating service to avoid exacerbating the issue. But understanding the underlying reasons for why your hot water heater is leaking is also integral to the whole process.

Water Leaking From Water Heater: Where From?

First, you need to understand that hot water heater leaking from the bottom is not the same as hot water tank leaking from the top or water coming out as condensate. While the tank/drain pipe leakage pretty much causes the same issues, the core problem may be different in all these cases. This applies to both electric and gas heaters.

Close-up image of a rundown water heater leaking, rusted to the core, requiring immediate attention

Now onto “why is my water heater leaking?”

What Causes a Water Heater to Leak?

Whether it’s a hot water tank leaking from the bottom or some moisture dripping from underneath and getting cold, or condensate leaking out, in all such cases, there is one similarity: a structural failure in the heater tank or associated parts necessitating immediate repair.

Here are the actual reasons:

Drain Valve

Issues with the drain valve can often lead to the top of the water heater leaking for both electric and gas-powered heaters. The drain valve normally provides an exit for the excess water, but if it fails, moisture can find its way through, resulting in visible leaks.

Too Much Pressure

Boiler tanks are designed to tolerate pressure, this is an integral element in their working principle. However, too much of anything can be bad. Many times, it is not the structural defects of the tank itself but excessive pressure instead that leads to water leaking from the water heater.

Faulty Temperature And Pressure Relief Valve

This is another common issue leading to leakages – if the pressure relief valve (which is not the same as the drain valve) or the temperature apparatus starts malfunctioning, condensation can appear on the tank surface, signaling a leak. Many people who wonder “why my water heater is leaking,” have this issue and must seek an immediate replacement for the defective parts.

Old Tank

Well, let's face it – there's a general life expectancy for everything, including water heater tanks. They won't last forever, and you should not expect them to do so. Many people exhaust their Google searches with queries like "why is my hot water heater leaking” without realizing that the actual issue is the tank itself – it’s too old.


In many cases, sediment buildup, especially the charged/ionic fraction (calcium and magnesium ions, for instance) can lead to leaks. We have had many clients wondering “what to do if your water heater is leaking," and the answer in this situation would be to call over the professionals and have them thoroughly clean and repair the tank – a small fix just won't do!

Cracked Storage Tank

Lastly, the integrity of the storage tank itself can be the issue. If the tank is cracked (due to some surface-level damage or if it is of poor construction), you can expect all sorts of leakage issues.

After exploring all these aforementioned leakage issues, you should be able to take resolute steps if you see a hot water heater leaking from the top hot water outlet or something else of the sort.

What To Do If Water Heater Is Leaking

A team of competent handymen can help find the perfect solution for water under the water heater for your recent system. Moreover, our specialists understand what causes a water heater to leak, and will help you discover what is specifically wrong with your system.

Image of water leaking from water heater; leakage emergency necessitating immediate technical help

We guarantee excellent service for water heater drips and any related heating and cooling services to our Austin area customers. People worried about gas water heater leaking from the bottom will find much solace in our friendly and experienced team, which is always eager to help and offer exceptional performance.

Call Over the Pros from Smart Air to Fix Your Water Heater

Now that you understand “why do water heaters leak,” you should also know to call the reliable and trusted professionals from Smart Air Cooling and Heating to help, even if your hot water heater leaks occasionally. We serve clients throughout Austin, in all major areas, such as:

  • Westlake 
  • Rolling Wood 
  • Dripping Springs
  • Buda

Call now for an appointment or emergency services, we are available either way!