The answer to 'how to maintain water heater' is to perform regular maintenance tasks to ensure your water heater is operating safely and efficiently. This includes draining the tank to remove sediment, checking the temperature and pressure relief valve, and inspecting the anode rod. It's also important to insulate the tank and pipes to prevent heat loss.
Maintaining your water heater can extend its lifespan and help prevent costly breakdowns. However, for any major repairs or replacement, it's best to call a professional HVAC technician who can properly service the unit and ensure it meets all safety standards.