Rinnai RH180 Installation Fundamentals page 44

Maintenance - Tank
• Drain the water from the tank at least once per year. This will remove excess
sediment from the bottom of the tank. Accumulated sediment will reduce the
efficiency and life expectancy of the tank.
• Manually operate the relief valve at least once per year.
• The water heater is equipped with an anode rod that is designed to prolong the
life of the glass-lined tank. This anode is slowly consumed protecting the tank
from corrosion. The anode should be checked every two years. If more than
half of the anode has been consumed it should be replaced.
• In certain conditions, the anode rod can react with the water producing
discolored water or an odor. This can be a result of the reaction between the
anode and hydrogen sulfide gas dissolved in the water. For more information
see the "required maintenance" section of the operation and installation manual
under "Anode".
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