When you notice your water heater leaking from the top, it’s alarming. 

Here are some reasons you might see water coming from the top of your water heater, in order of severity:


1. Condensation


Sometimes, what appears to be a leak is actually just condensation. This happens when there’s a significant temperature difference between the water inside the tank and the surrounding environment. If it’s just condensation, it’s not a serious issue and generally doesn’t require repair since it doesn’t indicate a water heater malfunction.


2. Loose Cold Water Inlet and Hot Water Outlet Connections


These are the pipes that bring cold water into your water heater and send hot water out. If the connections are loose, water can start to leak from the top. While this issue is important to address, it’s relatively minor and can typically be resolved by simply tightening the connections with a wrench—but be careful not to over-tighten as this can damage the pipes. 


3. Bad Temperature and Pressure (T&P) Relief Valve


The T&P valve is designed to release water if either the temperature or pressure inside the tank gets too high, as a safety measure. If it’s not functioning correctly or if it’s loose, it can cause leaks. Replacing or tightening the valve can solve the problem. This is a more serious issue because a malfunctioning T&P valve can potentially lead to pressure issues in the tank. However, it’s often fixable by replacing or repairing the valve, and can be done yourself (if you’re handy) or by your local plumber.


4. Leaking from an Overhead Pipe


Sometimes, the leak might not be from the water heater itself but from a pipe above it. Water can drip down onto the top of the heater, creating the appearance of a leak. Check any overhead plumbing for leaks. How serious the emergency is depends on the severity of the leak in the overhead pipe. It’s not a direct issue with the water heater itself, but it can cause water damage and should be fixed as soon as you can.


5. Faulty Expansion Tank


If your system includes an expansion tank, it might be the source of the leak. Expansion tanks are used to absorb excess pressure. If they fail, it could lead to water leaking from the top of your heater. This is serious because a malfunctioning expansion tank can lead to consistent pressure problems, which will cause damage to the water heater and plumbing system.


6. Corrosion or Rusting


Over time, water heaters can develop rust or corrosion, especially at the top where moisture and metal meet. Corrosion and rust can compromise the integrity of the tank, leading to small holes or cracks through which water leaks. If corrosion is the cause, you likely need to replace your water heater, as patching up will only offer a temporary fix. This is one of the most serious issues that can happen with your water heater because it indicates deterioration of the unit, which usually leads to the need for replacement. 


7. Internal Tank Leak


If the internal tank has a leak, water can seep out and appear at the top of the unit. Unfortunately, this almost always means the water heater is nearing the end of its life and needs to be replaced, as internal tank leaks are often not repairable. They’re a significant problem because these leaks affect the core function of your water heater.


The average lifespan of a water heater is about 10-15 years. If your water heater is new, it’s more likely that the issue is one of the minor ones. However, as your water heater gets older, corrosion and internal leaks become more likely.


What do I do if my hot water heater is leaking from the top?


If your hot water heater is leaking from the top, start by turning off the power supply. (Switch off the circuit breaker for electric heaters or turn the gas valve to “off” for gas heaters.) 

Then, shut off the cold water supply to the heater. Identify where the leak is coming from, whether from loose cold water inlet and hot water outlet connections, the temperature and pressure (T&P) relief valve, or from corrosion

If connections are loose, gently tighten them with a wrench, but avoid overtightening. If the leak is from the T&P valve and it’s not simply loose, this could indicate excessive pressure, requiring a plumber’s attention. Check for any overhead pipes that might be causing the leak. After addressing the suspected cause, dry the area and monitor the water heater to ensure the leak has stopped. 

If the problem persists or you’re unable to identify the source, get the help of a professional plumber.


Should I turn off my hot water heater if it is leaking?


Yes, you should turn off your hot water heater if it is leaking. Doing so can help prevent further damage like:

Electrical or Gas Hazards. If the water heater is electric, you don’t want water potentially coming into contact with electrical components. For gas water heaters, shutting off the gas supply can prevent gas leaks if the heater is damaged.

Water Damage. Turning off the water supply to the heater minimizes the amount of water that can leak—reducing potential water damage to your home.

Pressure and Temperature Issues. If the leak is related to pressure or temperature issues inside the tank, shutting off the heater will help stabilize these conditions and prevent further problems.


Can you still use water if your water heater is leaking?


Yes, you can still use water if your water heater is leaking, but with limitations. You can freely use cold water as its supply is separate from the water heater. However, if you’ve turned off the water heater and its water supply due to the leak, which is recommended, you won’t have access to hot water. 

Avoid using the hot water system if the leak is substantial, to prevent worsening the issue. While you might be able to use hot water sparingly for essential needs if the leak is minor, this should only be a temporary measure until the leak is properly fixed.

We are licensed professional plumbers near the Rockford, Michigan area. For any concerns with your water heater, please contact us.


Is a leaking water heater an emergency?


Whether a leaking water heater constitutes an emergency depends on the severity of the leak. 

If the leak is minor and manageable, such as a few drips from a loose connection, it’s not necessarily an immediate emergency. You can often temporarily manage this by tightening connections or placing a bucket underneath. However, it should still be addressed quickly to avoid it getting any worse.

If the leak is significant, causing rapid water accumulation or a sudden burst, it’s an emergency. You don’t want water damage, mold growth, or structural integrity problems to compromise your home. Same with leaks near electrical systems, flooring, walls, or valuable items. 

If you suspect a gas leak (in the case of gas water heaters), treat it as an emergency.

Overall, having no hot water can be a significant inconvenience. If you’re unsure about the severity of the leak or how to handle it, it’s always wise to err on the side of caution and contact a professional plumber.


Call Us at 616-866-1921


Blakeslee & Son is a plumber based in Rockford, Michigan and serving the West Michigan area, including Grand Rapids, Cedar Springs, Rockford, Cascade, Wyoming, Hudsonville, and the surrounding areas. We offer emergency service every day from 8 AM to 8 PM.