How to Maintain Your Water Heater
To maintain your water heater, turn off the power or gas, test the TPR valve by lifting its lever, inspect the anode rod for corrosion, check for leaks around the base and fittings, confirm the temperature is set to 120 degrees Fahrenheit, and drain a quart of water to flush sediment. Do this once a year to prevent costly failures and extend the tank's lifespan.
- Time
- 30 min
- Frequency
- every year
- Difficulty
- medium
- Cost
- Free
What you'll need
- 1-1/16" socket wrench
- Garden hose
- Bucket
- Gloves
The steps
- 1
Turn off the power or gas
For an electric water heater, flip the dedicated breaker to OFF. For a gas unit, turn the gas control valve to PILOT. Never work on a water heater with the heating element active. This prevents burns and protects the element from damage if the tank is partially drained.
- 2
Test the TPR valve
The temperature and pressure relief valve is on the side or top of the tank with a discharge pipe running down toward the floor. Place a bucket under the discharge pipe, then lift the lever on the TPR valve for 2 to 3 seconds and release it. Water should flow freely and stop when you release the lever. If no water flows or the valve leaks afterward, replace it immediately. A failed TPR valve is a safety hazard.
- 3
Check the anode rod
The anode rod screws into the top of the tank. Use a 1-1/16 inch socket wrench to loosen and pull it out. A healthy rod is at least half its original diameter. If the rod is thinner than half an inch, coated in calcium, or the core wire is exposed, replace it. A new magnesium anode rod costs under $30 and takes 5 minutes to swap.
- 4
Inspect for leaks
Check the base of the tank, all pipe fittings, the drain valve, and the TPR discharge pipe for moisture, rust stains, or active drips. Small fitting leaks can often be fixed by tightening the connection. A leak from the tank body itself means the inner lining has corroded through and the tank needs replacement.
- 5
Verify the temperature setting
Check that the thermostat is set to 120 degrees Fahrenheit. This is hot enough to kill bacteria and meet household needs while reducing scalding risk and energy waste. On gas units, the dial is on the front of the gas control valve. On electric units, the thermostat is behind an access panel on the side of the tank.
- 6
Drain a quart to flush sediment
Place a bucket under the drain valve at the bottom of the tank. Open the valve and drain about a quart of water. If the water is cloudy or has visible particles, continue draining until it runs clear. For a full flush, see the dedicated guide on flushing your water heater.
- 7
Restore power and verify operation
Close the drain valve. Turn the breaker back on or set the gas valve to its normal operating position. Wait 30 to 60 minutes, then run a hot faucet to confirm the water heats properly. Check the drain valve and TPR valve one more time for drips.
Why annual maintenance matters
A water heater is one of the most expensive appliances in your home to replace. A new tank unit with installation runs $1,000 to $3,000 depending on size, fuel type, and local labor rates. Most tanks are rated for 8 to 12 years, but that lifespan assumes average conditions and no maintenance.
Annual maintenance pushes that lifespan to 15 years or more. The cost is 30 minutes of your time once a year and, occasionally, a $20 replacement part. That is a strong return on a small investment.
The two things that kill water heaters early are sediment buildup and tank corrosion. Sediment insulates the water from the heating element, forcing the unit to work harder and overheat the tank floor. Corrosion eats through the tank lining from the inside out. Both are preventable with the steps in this guide.
The anode rod: your tank's first line of defense
Every tank water heater has an anode rod threaded into the top of the tank. It is a steel core wire wrapped in magnesium, aluminum, or zinc. The rod exists to corrode so the tank does not. Water is corrosive to steel, and without the anode rod, the tank lining would start rusting within a few years.
This is called sacrificial corrosion. The anode rod attracts the corrosive elements in the water and absorbs the damage. Over time the rod dissolves. Once it is gone, the tank walls become the target.
Most anode rods last 3 to 5 years depending on water chemistry. Hard water and softened water both consume rods faster. Check the rod annually. If it is less than half an inch thick or the core wire is visible, replace it. A replacement rod costs $18 to $28 and takes 5 minutes to install with a 1-1/16 inch socket wrench. That small effort can add years to your tank's life.
TPR valve safety
The temperature and pressure relief valve is a safety device that prevents your water heater from over-pressurizing. If the temperature or pressure inside the tank exceeds safe limits, the valve opens and releases water through the discharge pipe.
Test it once a year by lifting the lever for a few seconds. Water should flow freely and stop when you release the lever. If the valve does not open, does not close, or drips continuously after testing, replace it. TPR valves cost $10 to $20 and are a standard DIY replacement.
Do not cap, plug, or remove the discharge pipe. It directs released water safely toward the floor. Without it, a pressure release would spray scalding water outward.
Signs your water heater is failing
Catch problems early and you can plan a replacement on your schedule instead of dealing with a flooded basement. Watch for these warning signs:
- Rusty hot water. If only the hot side runs rusty, the tank lining or anode rod is corroded. Flush the tank and check the anode rod. If the rod is spent and the water stays rusty, the tank lining is compromised.
- Rumbling or popping noises. This is steam trapped under a thick sediment layer. Flush the tank. If the noise returns quickly, sediment has hardened and a full flush may not clear it.
- Water pooling around the base. Check fittings and the drain valve first. If the leak is from the tank body itself, the inner lining has corroded through. The tank cannot be repaired and needs replacement.
- Inconsistent temperature. A failing thermostat, a burned-out heating element, or heavy sediment can all cause temperature swings. Start with a flush and check the thermostat setting before calling a professional.
- Age. If your tank is over 10 years old and has never been maintained, prioritize an inspection. The serial number on the rating plate typically encodes the manufacture date. Check the manufacturer's website for decoding instructions.
Replacing a water heater proactively before it fails gives you time to compare prices, schedule installation at your convenience, and avoid water damage from a sudden tank failure.
Frequently asked questions
- How long do water heaters last?
- Tank water heaters last 8 to 12 years on average without maintenance. With annual maintenance, especially anode rod replacement, many tanks reach 15 years or more. Tankless units last 15 to 20 years. The serial number on your tank usually encodes the manufacture date if you are unsure of the age.
- What is an anode rod?
- An anode rod is a metal rod, usually magnesium or aluminum, that threads into the top of the tank. It corrodes on purpose so the tank walls do not. This is called sacrificial corrosion. Once the rod is consumed, the tank lining starts corroding instead. Checking and replacing the anode rod is the single most effective thing you can do to extend your water heater's life.
- How do I know if my water heater is failing?
- The most common warning signs are rusty or discolored hot water, rumbling or popping noises from sediment buildup, water pooling around the base of the tank, inconsistent water temperature, and a unit older than 10 years that has never been serviced. Any leak from the tank body (not a fitting or valve) means replacement is imminent.
- Is maintenance different for tankless water heaters?
- Yes. Tankless units do not have an anode rod or a TPR valve in the same configuration. Their main maintenance task is descaling the heat exchanger by circulating white vinegar through it with a pump, typically once a year. They also have inlet filters that need periodic cleaning. The steps in this guide apply to traditional tank water heaters only.
Products you'll need
This section contains affiliate links. We may earn a commission at no cost to you.
Camco Magnesium Anode Rod
Universal replacement anode rod for the anode check step
Anode Rod Socket Wrench (1-1/16")
Socket needed to remove/install anode rod
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