Water heater maintenance comes down to a few simple tasks: flush the tank at least once a year, test the pressure relief valve, check the anode rod annually, and keep the temperature around 120°F. These steps clear out sediment, catch corrosion early, and help your water heater last longer with fewer costly repairs.
You count on your water heater every day, especially on cold winter mornings, but it is easy to forget until something goes wrong. This guide covers every water heater maintenance task, from checking the pressure relief valve to preventing sediment build-up, and when to bring in a professional.
Key Points
- Flush a tank water heater at least once a year to remove sediment.
- Test the pressure relief valve regularly; if no water flows when you lift the lever, replace the valve.
- Check the anode rod every year and replace it once it is less than 1/2 inch thick or coated with calcium.
- The U.S. Department of Energy recommends 120°F for most households.
- Tankless water heaters need descaling and filter cleaning instead of tank flushing.
What Type of Water Heater Do You Have?
Your water heater maintenance routine depends on the type of unit you have. Check the type, capacity, and the manufacturer’s maintenance instructions before you start.
There are two main types. A storage tank water heater keeps a set amount of water hot at all times. A tankless water heater stores no water and heats it as it flows through the unit.
Capacity matters too. Whether your tank holds 30 gallons or 80, knowing its size tells you how much hot water it can supply and how long it takes to reheat.
Why Does Water Heater Maintenance Matter?
Regular water heater maintenance extends your unit’s lifespan, keeps it running efficiently, and cuts the chance of unexpected breakdowns and costly repairs.
Sediment builds up in the tank over time. It insulates the water from the burner or elements, so the water heater works harder and uses more energy. Flushing the tank removes it, so your water heats faster and more efficiently.
The pressure relief valve is a safety feature that releases excess pressure if the tank pressure climbs to dangerous levels. Routine checks confirm the valve works when you need it.
Regular inspections of the tank and its components catch early signs of wear, corrosion, or leaks. Early detection lets you fix small problems before they become major malfunctions.
Water Heater Maintenance Schedule
Use this schedule to keep track of each water heater maintenance task.
|
Task |
How Often |
Why It Matters |
|
Drain and flush the tank |
At least once a year |
Removes sediment that lowers efficiency and causes corrosion |
|
Inspect the anode rod |
Once a year |
Catches a worn rod before the tank starts to corrode |
|
Test the pressure relief valve |
Regularly |
Confirms the main safety valve opens when needed |
|
Check the temperature setting |
When you notice changes in hot water |
Balances scald safety, comfort, and energy use |
|
Check heating elements (electric) |
Regularly |
Finds a failed element before you lose hot water |
|
Professional inspection |
Regularly |
Spots corrosion, leaks, and part wear a homeowner may miss |
Safety Precautions Before You Start
Water heater maintenance means working around water, electricity or gas, and hot surfaces, so take these precautions first:
- Shut off the power: Turn off the circuit breaker or unplug the heater before you begin.
- Wear protective gear: Safety gloves, eye goggles, and rubber-soled shoes protect you from accidents.
- Keep a clean workspace: A clutter-free area lowers the risk of tripping or knocking over tools.
- Keep a fire extinguisher handy: Electrical fires are unlikely, but being prepared matters.
- Stay grounded: Ground yourself when working on electrical appliances to avoid shocks.
How to Drain and Flush a Water Heater Tank
Draining and flushing the tank removes sediment buildup and improves performance. You need a garden hose, a bucket, and gloves.
- Shut off the power source. For an electric heater, turn off the circuit breaker. For a gas heater, turn the gas control valve to the “pilot” setting.
- Connect a garden hose to the drain valve at the bottom of the tank, and run the other end to a lower spot where hot water will not cause damage.
- Open the drain valve slowly and let the water flow until it runs free of sediment. This may take up to 20 minutes. Watch for changes in color or clarity.
- Open a hot water tap in the house to let air into the system and help the tank drain.
- Close the drain valve and remove the hose once the water runs clear.
- Refill the tank by opening the cold water supply valve.
- Restore power only after the tank is full and a steady stream of water runs from the hot water tap.
How to Test the Pressure Relief Valve
The pressure relief valve releases pressure when the water temperature or pressure in the tank gets too high. It is one of the most important safety parts on your water heater, so test it regularly.
- Locate the valve. It is usually on the top or side of the tank.
- Raise and lower the test lever several times. Water should rush out of the overflow pipe.
- Replace a valve that does not flow. If no water comes out, the valve is faulty.
- Watch for leaks afterward. Drain a little water carefully to avoid scalding. If the valve keeps leaking after the test, replace it.
- Check for warning signs. Rust, leaking water, or mineral deposits around the valve point to a failing valve.
How to Inspect the Anode Rod
The anode rod protects your water heater tank from rust and corrosion, so check it once a year. The rod is usually magnesium or aluminum around a steel core. It attracts corrosive elements in the water and wears away over time instead of the tank. Once the rod is used up, the tank itself starts to corrode.
The anode rod usually sits on top of the water heater. Unscrew it and pull it out to examine it. Replace the rod if it is less than 1/2 inch thick or coated with calcium. Some thin or pitted spots are normal and show the rod is doing its job.
When you buy a new anode rod, make sure it is compatible with your water heater model. Recheck it in a year.
What Temperature Should Your Water Heater Be Set To?
Most households should set the water heater to 120°F. Many water heaters ship set to 140°F, but the U.S. Department of Energy recommends 120°F for most homes. Too high a setting risks scalding, while too low a setting can allow bacterial growth.
To adjust the temperature:
- Find the thermostat. It is usually a dial or digital panel on the side of the tank.
- Check the current setting. Note where it is set before you change anything.
- Turn off the power for your safety while you make the adjustment.
- Adjust the dial slowly, then give the water time to reach the new setting.
- Test the water. After a few hours, check the temperature at a tap with a thermometer.
How to Check the Heating Elements on an Electric Water Heater
Heating elements do the work in an electric water heater. A failed element leaves you with cold showers and a repair bill.
Test the elements. With the power off, use a multimeter to measure resistance. A faulty element shows no resistance. If you are not comfortable using a multimeter, call a professional.
Replace a failed element. Confirm the power is off, drain the tank below the element, remove the old element with an element wrench, and install the new one.
Watch for leaks. Even a small leak around an element can cause significant damage over time, so check the elements and surrounding area regularly.
How to Prevent Sediment Build-Up
Sediment build-up lowers efficiency, raises energy costs, and can lead to early water heater failure. These strategies keep it in check:
- Drain the tank regularly: Flushing at least once a year is the simplest way to control sediment.
- Install a sediment trap: A sediment trap catches particles before they reach the water heater.
- Use a water softener: In hard water areas, a softener reduces the minerals that settle in the tank. Our water filtration installation service can help improve the water entering your system.
- Monitor water quality: Cloudy or dirty hot water can signal a sediment problem.
- Lower the temperature: A lower temperature setting helps reduce sediment build-up.
How Is Tankless Water Heater Maintenance Different?
Tankless water heater maintenance focuses on scale, not sediment, because there is no tank to flush. Minerals in the water collect on the heat exchanger as water flows through the unit.
- Descale the unit: Flushing the heat exchanger with a descaling solution or white vinegar removes mineral buildup. Follow the manufacturer’s instructions for your model.
- Clean the inlet filter: Most tankless units have a small screen on the cold water inlet that traps debris and should be rinsed during maintenance.
- Check the venting: Gas tankless units need clear, intact venting to operate safely.
Thinking of switching? Our tankless water heater installation team can walk you through the maintenance a tankless unit needs before you decide.
When to Call a Professional for Water Heater Maintenance
Some water heater maintenance problems take a trained eye to spot, even when you keep up with your own checks. A professional inspection can find corrosion, leaks, or sediment build-up you might miss.
During a professional visit, a technician can confirm the pressure relief valve and other key components work correctly, flush the system, replace worn parts, and set the thermostat properly. If the inspection turns up a problem, our water heater repair specialists can fix it on the spot or recommend the best next step. When a unit is past saving, we also handle water heater replacement.
Frequently Asked Questions
How often should you flush a water heater?
Flush a tank water heater at least once a year. Regular flushing removes the sediment that settles at the bottom of the tank, lowers efficiency, and can cause corrosion. Homes with hard water may benefit from flushing more often, since minerals build up faster.
How do you know when an anode rod needs replacing?
Replace the anode rod when it is less than 1/2 inch thick or coated with calcium. Pull the rod and inspect it once a year. Some thin or pitted areas are normal, since the rod is designed to corrode instead of the tank. A rod that is mostly gone means the tank is no longer protected.
What temperature should a water heater be set to?
The U.S. Department of Energy recommends 120°F for most households. Many water heaters ship set to 140°F, which raises energy use and the risk of scalding. Setting the water heater too low can allow bacterial growth, so 120°F is the usual balance.
Can you do water heater maintenance yourself?
Yes, homeowners can handle basic water heater maintenance like flushing the tank, testing the pressure relief valve, and adjusting the temperature. Tasks involving electrical testing, gas components, or part replacement are safer for a professional. A regular professional inspection also catches problems a homeowner may miss.
Keeping up with water heater maintenance is the easiest way to avoid a cold shower and a surprise repair bill. At Pro Comfort Control AC & Heating Installation, our certified technicians inspect your water heater, explain what we find, and give you upfront pricing before any work begins. Schedule your appointment today and keep the hot water flowing.