Saturday, January 25th, 2025
Ask Allied: Why is my water heater leaking?

We usually don’t think much about our water heater until we step in the shower too late to learn there’s no hot water, or after we see huge puddles of water on the basement floor. But here at Allied Reddi-Rooter, we repair and replace water heaters on a regular basis. While sometimes a visit from the plumber is needed to address a leaking water heater, occasionally you can identify – and even fix – the problem yourself.
Let’s dive into the most common causes of a leaking water heater and what you can do about it.
1. Condensation or humidity
One of the easiest and least worrisome reasons for a water heater leak is condensation. If your water heater is in a basement or garage (where the air is cooler and more humid), condensation can form on the outside of the tank, making it look like there’s a leak. This is more common in older water heaters or during extreme weather changes.
What to do: If it’s just condensation, you’re in the clear. However, to prevent future issues, you might want to check for proper insulation around your water heater to help regulate temperature and reduce humidity.
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2. Loose or broken connections
Another reason your water heater might be leaking is due to broken connections. The inlet and outlet pipes carry water into and out of the tank. If these connections aren’t tight, or if the pipes themselves have corroded, you could end up with a slow drip or a more serious leak.
What to do: Check the connections for any visible water or dampness. If you find a loose connection, it’s worth tightening it carefully. If you spot corroded or cracked pipes, they may need replacing. It’s always a good idea to call in a plumber to make sure the job is done right.
3. Leaking pressure relief valve
Your water heater is equipped with a temperature and pressure relief valve (T&P valve), which helps prevent excess pressure from building up inside the tank. If this valve is faulty or if the pressure is too high, water can start leaking from the valve.
What to do: First, check to see if the water is coming from the valve itself. If it is, it could be because the temperature setting is too high or the water pressure in your home is too high. A plumber can test and replace the valve if needed, and in some cases, adjusting your home’s water pressure might do the trick.
4. Tank corrosion
As your water heater ages, it can start to corrode, especially if it hasn’t been properly maintained. The inside of the tank is lined with a special coating to prevent rust, but over time, this coating can break down. When the tank starts to rust, tiny holes or cracks can form, causing water to leak from the tank.
What to do: Unfortunately, once a tank begins to corrode, it’s usually a sign that it’s time to replace the water heater. If your water heater is over 10 years old, it may be worth calling a professional plumber to assess the situation. In some cases, replacing the unit might be the most cost-effective solution.
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5. Sediment buildup
Over time, minerals from hard water can build up inside the tank and settle at the bottom. This sediment can cause the tank to overheat and increase the pressure inside, potentially leading to a leak. Additionally, if the sediment buildup is severe, it can damage the tank’s lining, contributing to leaks.
What to do: Regular maintenance, including flushing your water heater to remove sediment, can prevent this issue. If you haven’t flushed your water heater in the last year or two, it’s a good idea to have a professional handle it. Flushing the tank helps ensure it runs efficiently and can extend its lifespan.
6. Cracked tank
In rare cases, a water heater’s tank can crack due to pressure, freezing temperatures, or simply wear and tear. When this happens, the only solution is usually to replace the unit, as cracks in the tank are not repairable.
What to do: If you discover a crack, call a plumber right away. Unfortunately, a cracked tank is one of those situations where repairs aren’t feasible, and you’ll need to replace the entire water heater.
A leaking water heater is never something to ignore. Whether it’s condensation, a faulty valve, or a more serious issue like tank corrosion, catching the problem early can help prevent costly water damage. If you’re ever in doubt, don’t hesitate to reach out Allied Reddi-Rooter. We can make sure your water heater is functioning properly.