A water heater usually gives some warning before it fails. If you know your unit's age and what to look for, you can plan a replacement on your schedule instead of dealing with a cold shower or a flooded basement in January.
Typical water heater lifespan
According to the U.S. Department of Energy, storage tank water heaters last 10 to 15 years, and most tankless water heaters have a life expectancy of more than 20 years. You can read the comparison in the Department of Energy guide to tankless water heaters.
Your unit may last longer or shorter than that range. These factors make the biggest difference:
- Maintenance: Regular flushing and anode rod checks slow corrosion and sediment buildup.
- Water hardness: Hard water leaves mineral deposits in the tank or heat exchanger. If your home has hard water, plan on more frequent flushing or descaling.
- Installation quality: Correct venting, sizing and water pressure reduce strain on the unit.
- Usage: A unit that runs hard for a large household wears faster than one serving one or two people.
How to find your water heater's age
Most water heaters have a rating plate (a sticker or metal label) on the side of the tank. It lists the model number and serial number. Many manufacturers code the manufacture date into the serial number, often as a letter or digits that stand for the month and year. Each brand uses its own format, so look up your brand's serial number format on the manufacturer's website or ask a technician to read it for you.
If you bought the house with the water heater already installed, check your home inspection report. It often lists the unit's approximate age.
Signs your water heater is wearing out
Watch for these warning signs:
- Water around the base of the tank. A leak from the tank itself usually means the steel has corroded through. A tank leak cannot be repaired.
- Rusty or discolored hot water. If only the hot water is discolored, the inside of the tank may be rusting.
- Rumbling or popping noises. These sounds usually come from sediment on the bottom of the tank. Heavy sediment makes the unit work harder.
- Less hot water than before. Sediment takes up space and insulates the water from the burner, so you run out faster.
- Water that never gets hot enough. This can point to a failing gas valve, thermocouple, burner, or electric heating element.
- Corrosion on fittings and connections. Rust on the water lines, valves or the top of the tank is a sign of slow leaks or tank deterioration.
- Frequent repairs. If you have paid for several repairs in a short time on an older unit, more failures are likely.
What you can safely check yourself
You can do these checks without tools or special training:
- Look at the floor around the water heater and the drain pan, if you have one. Note any water, rust stains or white mineral deposits.
- Look at the pipe connected to the temperature and pressure relief valve on the side or top of the tank. If water is dripping from the end of that pipe, call a professional. Do not cap or plug it.
- Run hot water at a faucet into a clear glass. Compare its color to the cold water.
- Listen to the tank while it is heating. Note any popping, crackling or rumbling.
- Read the rating plate and write down the model and serial number for your technician.
Do not open gas burner access panels, remove electrical covers, or try to relight a gas unit that keeps going out. If you smell gas near the water heater, leave the house right away, do not use light switches or phones inside, and call 911 and your gas utility from outside.
Repair or replace?
Some problems are worth repairing. A failed thermocouple, gas control valve, heating element or thermostat can often be replaced on a unit that is otherwise in good shape.
Replacement usually makes more sense when:
- The tank itself is leaking.
- The unit is near or past the 10 to 15 year range and needs a major part.
- Your household has outgrown its capacity and you regularly run out of hot water.
- You want to change fuel type or switch to a tankless or heat pump model.
Replacing a unit before it fails gives you time to compare options instead of taking whatever is available on an emergency call. If you are unsure what size to buy, a technician can review your household's peak hot water use.
When to call a professional
Call for service if you see water leaking from the tank, if the relief valve pipe is dripping, if your hot water is rusty, or if your unit is more than 10 years old and showing any of the signs above. Call right away if you have no hot water during a cold snap or if water is spreading across your basement floor. Krinkie's offers water heater repair and replacement and 24-hour emergency service for urgent problems.
Common questions
How long does a tank water heater last?
The U.S. Department of Energy says storage tank water heaters last 10 to 15 years. Maintenance, water hardness and how hard the unit works all affect where yours falls in that range.
Can a leaking water heater tank be repaired?
No. If water is leaking from the tank itself, the tank has corroded through and the water heater needs to be replaced. Leaks from fittings or valves can often be repaired.
Why does my water heater make popping noises?
Popping or rumbling usually comes from sediment on the bottom of the tank. Flushing can help on a newer unit, but heavy sediment in an older tank is often a sign it is wearing out.