Water Heater Maintenance Checklist: Signs You Need Professional Service

Tank Water Heaters Store Hot Water, Tankless Models Heat on Demand

Tank water heaters require anode rod inspections, sediment flushing, and pressure relief valve testing during annual service visits. Tankless models skip these tasks but need descaling, which means flushing out mineral deposits that build up inside the unit where water gets heated, especially in areas with hard water.

The Parts Professionals Check During Maintenance

Technicians look at the parts that wear out over time and cause common issues with hot water heaters:

• Heating Elements: Electric models have two elements that can get coated with mineral deposits. Technicians test both since one might fail while the other keeps working. If that happens, you could still get some hot water, but not as much as you need.
• Gas Burners: Gas models need their burners checked to make sure they're heating correctly and that the flame looks right.
• Thermostat: Controls your water temperature. When it starts drifting or quits working, your showers go from scalding to lukewarm without warning.
• Anode Rod: The rod slowly corrodes so that your tank doesn't. Professionals pull it out to see how much metal is left before your tank starts rusting from the inside.
• Temperature and Pressure Relief Valve: A professional checks the relief valve to ensure that during a temperature or pressure emergency, the valve can safely discharge.

If you hear your water heater making noises like popping or rumbling, sediment could be sitting at the bottom indicating it needs to be flushed.

Catching problems early saves money and prevents a complete system failure:

Your Hot Water Isn't Hot Enough (Or Doesn't Last)

If your water isn't getting as hot as it used to, or if the temperature goes up and down without warning, a few issues could be to blame. Sediment buildup on heating elements or a thermostat that's starting to fail can affect how hot your water gets.

What starts as slightly cooler showers can progress to a complete loss of hot water if left unaddressed. Running out of hot water faster than normal suggests sediment has reduced your tank's effective capacity, heating elements are weakening, or your household's needs have outgrown your current unit.

Water Leaks, Rust Stains, or Moisture Around the Tank

Any moisture around your water heater deserves an immediate investigation. Small drips can indicate loose connections that a professional can tighten quickly. Larger water leaks might mean your tank is corroding, your pressure relief valve has failed, or fittings have worn out—all requiring prompt professional service.

Rust-colored water from your hot water taps suggests the anode rod has been completely used up, and the tank may be failing due to electrolysis or a weld crack. Corrosion on external fittings means moisture is getting into places it shouldn't, and the problem will get worse if someone doesn't fix it.

Popping Sounds, Rotten Egg Smells, or Hissing Noises

Popping, rumbling, or crackling sounds during heating cycles potentially point to sediment buildup at the bottom of the tank. While not dangerous, sediment reduces efficiency and accelerates tank wear.

A rotten-egg smell in your hot water usually comes from bacteria reacting with the anode rod. Rust-colored water from your hot water taps can also point to the same cause. Hissing or sizzling sounds near gas water heaters might indicate water dripping onto the burner—these sounds warrant immediate professional inspection for safety.

A water heater leaking hot water around the base means something's failing—get a technician to check it as soon as possible before you're mopping up a flooded basement.

Your water heater usually gives you warning signs before it fails completely. Some problems start small and get worse over weeks or months. Others need immediate attention:

Testing the Pressure Relief Valve and Flushing Sediment

The pressure relief valve stops your water heater from over-pressurizing if pressure gets too high. It opens at 150 PSI and fully opens at 210°F, ensuring that if the thermostat sticks and the ECO fails at the same time, liquid water is discharged instead of superheated water that could flash to steam. Technicians open the valve to make sure water flows out, then check that it closes without dripping. If the valve sticks or leaks after testing, technicians replace it on the spot.

Sediment settles to the bottom of your tank, like sand in a bucket. Flushing means draining water out through the drain valve until it runs clear. Sometimes the sediment clogs the drain valve itself, which is why technicians bring tools to clear blockages or replace the valve if needed.

Checking the Anode Rod and Testing Heating Elements

The anode rod sits at the top of your tank and slowly 'dissolves' so your tank doesn't. You should inspect it yourself or have a professional do it once a year to check for visible wear, and have a professional examine it every 5 years. Technicians unscrew it to see how much metal remains. Once the rod's mostly gone or 6 inches of core wire is exposed, your tank starts rusting from the inside out. Replacing the rod before it's completely used up can add years to your tank's life.

Heating elements burn out when mineral deposits coat them or the element itself wears out. Technicians shut off power, test each element with a meter, and replace any that fail. They also check the rubber gasket around each element, since a worn gasket can leak water into your home.

Gas Burner Inspection and Combustion Testing

Technicians check gas water heaters annually to see if the burners are working and exhaust gases are venting outside. They look at the flame, test for carbon monoxide, and check the vent pipe for blockages. A yellow or weak pilot light means the gas flow or air supply is off, which wastes money and can be dangerous.

Have your hot water heater serviced once a year. If you have hard water in your area, get it serviced twice a year since mineral buildup happens faster:

• Gas Models: Check the combustion system for safe operation.
• Tankless Units: Flush out mineral deposits.
• Heat Pump Models: Clean the air filter and check the heat pump.

Regular Water Heater Maintenance Costs Less Than Emergency Repairs

Regular water heater maintenance visits cost a fraction of what you'll pay for emergency repairs when your water heater fails at the worst possible time. Emergency calls cost more, and you're stuck without hot water while you wait for a technician to become available.

Annual maintenance finds problems while they're still cheap fixes. Replacing a worn anode rod or bad heating element during a service call beats paying for a flooded basement or emergency replacement. Skip maintenance, and you might void your warranty, leaving you to cover repair bills out of pocket.

Neglected water heaters work harder and waste energy. Sediment buildup and worn components force your system to use more electricity or gas to heat the same amount of water, which adds up on your utility bills month after month.

For over 80 years, A. O. Smith has manufactured water heaters that deliver reliable hot water when you need it. Our certified contractor network receives hands-on training on ProLine® tanks, Voltex® heat pump systems, and ADAPT® tankless units, so they know the specific preventative maintenance requirements for each model.

Regular water heater maintenance from a contractor trained on your water heater keeps it running longer and catches problems before they turn into expensive repairs. Connect with a certified A. O. Smith contractor for water heater maintenance and service.