Water Heater Maintenance: What Actually Helps
A little maintenance can help a water heater last and work better. Here is what is worth doing, how often, and what to leave to a plumber.
Updated November 12, 2026 · By the Water Heater Repair Raleigh team
For a tank water heater, the main maintenance tasks are flushing sediment from the bottom of the tank, checking the anode rod, and testing the temperature and pressure relief valve. Tankless units need periodic descaling and inlet filter cleaning. Follow the manufacturer's schedule in your owner's manual. Raleigh city water is classified as soft, which helps, but well water can be much harder.
Flushing a tank
Sediment settles at the bottom of a tank and can cause popping or rumbling sounds and reduce efficiency. Flushing drains some water through the drain valve to carry sediment out. Turn off the power or gas first, and be careful: the water is hot. On an old tank, an old drain valve may not close properly after flushing, so some homeowners leave this to a plumber.
The anode rod
The anode rod is a metal rod inside the tank that corrodes so the tank doesn't. Once it is used up, the tank starts to corrode. A plumber can check and replace it. A rotten-egg smell in the hot water is sometimes linked to the anode rod.
Testing the relief valve
The temperature and pressure (T&P) relief valve is a safety device. Manufacturers describe how to test it. Discharged water is scalding, so make sure the discharge line is in place. If the valve drips afterwards or won't seat, it needs replacing.
Tankless descaling
Minerals in water build up in a tankless heat exchanger. Descaling flushes a cleaning solution through the unit via its service valves. Clean the inlet water filter at the same time. See tankless water heater help.
What Raleigh's water means for you
The City of Raleigh's 2025 water quality report lists average total hardness of about 1.4 to 1.5 grains per gallon at its two treatment plants, classified as soft. Soft water slows scale buildup, but it doesn't stop sediment or anode wear. If you're on a private well, have your water tested.
What to leave to a plumber
- Anything involving gas connections, burners or venting.
- Replacing elements, thermostats or the anode rod if you're not comfortable with it.
- A drain or relief valve that won't close after testing.
Frequently asked questions
How often should I flush my water heater?
Follow the manufacturer's recommendation in the owner's manual. It depends on your water and how much hot water you use.
Does Raleigh have hard water?
City of Raleigh water is classified as soft in the city's 2025 water quality report (about 1.4 to 1.5 grains per gallon on average). Private wells can differ.
Can maintenance fix a leaking tank?
No. Maintenance can help a tank last, but a tank that leaks from its body needs to be replaced.
Related help
No hot water or a leaking tank?
Turn off the power or gas to the heater and close the cold-water valve above it if water is leaking. Then get help from an independent local plumber.