Rinnai Demand Duo R-Series Installation And Operation Manual page 43

Topics in this section
• Diagnostic Codes
Anodes
The storage tank is equipped with two
magnesium anodes designed to extend the life of
the storage tank. Slowly consumed over time, the
anode protects the glass-lined tank from
corrosion. It is strongly recommended to inspect
the anodes every two (2) years. If more than half
of the anodes have been consumed, they should
be replaced.
The longevity of the storage tank can be reduced
when a water softener is introduced to fight hard
water. Sodium salts added by a softener can
make the water extremely conductive; therefore,
the anodes are consumed at a faster rate. In
such conditions, the anodes should be inspected
on a yearly basis.
In certain conditions, the anodes may react with
the water, producing discolored or smelly water.
The most common complaint is hot water that
smells like rotten eggs. This is the result of the
reaction between the anode and hydrogen
sulphide gas dissolved in the water, which is
common in well systems. This issue can usually
be eliminated or reduced by changing the
magnesium anodes to aluminum anodes and by
chlorinating the storage tank and plumbing
system. If the problem continues, special filtration
equipment may be required. Under no
circumstances are the anodes to be removed
from the water heater on a permanent basis.
Removal of the anodes will lead to premature
failure of the water heater and will void the
warranty.
Anode
Replacement
Figure 38
Procedure
1. Remove
plastic caps.
2. With 1-1/8
in. socket
wrench,
remove the
anode.
Demand Duo™ R-Series (REC) Installation and Operation Manual
Storage Tank
Drain water through the drain valve at least once
a year. This will remove excess sediment from
the bottom of the tank. This sediment, if allowed
to accumulate, will reduce the efficiency and the
life of the tank.
Draining the Storage Tank
To completely drain the storage tank:
1. Turn the power "OFF" to the system by
disconnecting power to the system. (The
system will not be fully shut down by simply
pressing the power button on the controller.)
2. Close the cold water supply manual shut-off
valve.
3. Connect one end of a garden hose to the
storage tank drain valve and put the other
end next to a free-flowing drain.
4. Open the drain valve by turning the knob
counter clockwise.
5. Open a hot water faucet to allow air into the
system.
Figure 39
Drain Valve
Note: The cold water inlet can be installed
either at top or bottom of unit.
Cold Water
Supply Valve
43