Where water heaters leak
- The bottom of the tank. Rust through here means the tank is done.
- Supply connections on top. Often a loose or corroded fitting that a plumber can fix.
- The relief valve and its pipe. It may be doing its job because pressure or temperature is too high, or the valve may be failing.
- The drain valve near the bottom, which can drip after years of scale.
A slow leak from the tank or failed supply lines are the most common causes in an industry study cited second hand in our research. A leak from the tank body itself is not something to patch.
How hard valley water ages a tank
The Las Vegas Valley Water District rates its water very hard and tells customers to set treatment systems for 16 grains per gallon, or 280 ppm. North Las Vegas Utilities calls its water hard as well, from calcium and magnesium. Minerals settle in the bottom of a tank heater as scale. Scale makes the heater work harder and can hide the start of corrosion.
LVVWD also says to set the water heater to the maker's setting. Too high overheats the water and can push warm water back into cold lines. Too low can let bacteria grow.
How old is too old
| Type | Expected life, InterNACHI |
|---|---|
| Tank water heater | 6 to 12 years |
| Tankless water heater | About 10 years |
The date is usually on the label. If yours is near the end of that range and sits in a garage or hall closet against drywall, plan the swap before the leak plans it for you.
Shut it down safely
- Turn off the power at the breaker for an electric heater, or set a gas heater's control to off or pilot.
- Close the cold water valve on the line going into the top of the heater.
- If water is still coming, close the house main.
- Keep people away from the relief valve pipe. It can release very hot water.
- Take photos and call a plumber.
Can you still use water
With the heater's cold supply valve closed, you can usually still use cold water in the rest of the house. You will not have hot water until it is fixed. If you had to close the main, you have no water until the heater line is capped or fixed.
The water damage part
Garage and closet heaters soak the drywall and the wood bottom plate behind them, and the water spreads across the slab into the next room. Garages get hot in summer, and the North Las Vegas station averages 85 days a year at 100 degrees or more. Heat speeds up how quickly clean water turns dirty. Pull the water out, check the walls with a meter, and open only what the readings say.