A water heater that’s leaking is never something to ignore. Even a small drip can point to a bigger problem inside the tank or nearby plumbing. In some cases, a repair is enough. In others, replacement is the safer option to avoid water damage, loss of hot water, or safety risks.
Below, we’ll break down the most common reasons water heaters leak, how to tell where the water is coming from, and how to decide between water heater repair or replacement.
Common Causes of a Leaking Water Heater
Loose or Damaged Plumbing Connections
Water heaters connect to your home’s plumbing at several points. Over time, fittings can loosen, washers can wear out, or pipes can corrode. Leaks around the top or sides of the tank often come from these connections rather than the tank itself.
These issues are usually repairable, especially when caught early. A professional inspection can confirm whether tightening or replacing a fitting will solve the problem. This is often handled during standard water heater repair service.
Temperature and Pressure Relief Valve Leaks
The T&P valve is a safety feature that releases water if pressure or temperature inside the tank gets too high. If you notice water dripping from a discharge pipe, the valve may be doing its job or failing.
Common reasons include:
- Excess pressure in the system
- A faulty valve
- A missing or failed expansion tank
When system pressure is the issue, installing or repairing an expansion tank can stop the leak and protect the water heater from future damage.
Expansion Tank Problems
Homes with closed plumbing systems often rely on expansion tanks to absorb pressure caused by heated water expanding. If the expansion tank fails or becomes waterlogged, pressure can build up and force water out of valves or fittings.
Leaks related to pressure problems don’t always start at the water heater itself, which is why a full plumbing evaluation is important. Expansion tank issues are common and usually repairable when addressed early.
Water Heater Leaking From the Bottom
A water heater leaking from the bottom is one of the most concerning signs. While it could still be related to a valve or fitting, it often points to internal tank damage.
Inside traditional tank water heaters, corrosion slowly eats away at the metal lining. Once the tank itself starts leaking, repairs are no longer effective. In these cases, replacement is usually the only safe option.
Sediment Buildup Inside the Tank
Over time, minerals in the water settle at the bottom of the tank. This sediment can:
- Cause overheating
- Crack the internal lining
- Accelerate corrosion
Sediment-related damage is a common reason older tanks fail. Flushing the tank regularly can help prevent this, but once the tank structure is compromised, replacement is recommended.
Tankless Water Heater Leaks
Tankless systems don’t store water, but they can still leak. Common causes include:
- Failed internal seals
- Loose connections
- Scale buildup damaging internal components
Tankless leaks are often repairable, especially when addressed quickly. In some cases, replacement may be recommended if internal components are heavily damaged or outdated. Professional tankless water heater installation and replacement ensure proper sizing and long-term reliability.
Is a Leaking Water Heater Dangerous?
Many homeowners ask, “Is a leaking water heater dangerous?” The answer depends on the cause, but it can be.
Potential risks include:
- Water damage to floors, walls, and nearby appliances
- Electrical hazards if water reaches wiring or controls
- Increased pressure that stresses the tank
- Sudden tank failure or rupture
If you see pooling water, rust-colored leaks, or hear unusual noises, it’s best to shut off the water supply and call a professional right away.
Water Heater Repair vs Replacement
Deciding between water heater repair vs replacement usually comes down to a few key factors:
- The age of the unit
- Where the leak is coming from
- Visible corrosion or rust
- Overall system condition
Valves, fittings, expansion tanks, and many tankless issues can often be repaired. Leaks from the tank itself usually mean replacement is the safer choice.
When to Call a Professional
If your water heater is leaking, it’s best to act quickly. Universe Home Services brings over 65 years of experience, multi-licensed technicians, same-day service, 24/7 phone support, and financing options to make water heater repairs or replacements straightforward and stress-free.
Schedule water heater repair or replacement with Universe Home Services today.
