Freeze Protection - Rinnai RUCS65i series Installation And Operation Manual

Unit clearances
Indoor models:
to Combustibles
RUCS65i,
inches (mm)
RUCS75i
Top of Heater
Back of Heater
Front of Heater
Sides of Heater
Ground/Bottom
Vent
* 0 inches from vent components and condensate drain
line.
The clearance for servicing is 24 inches in front of the
water heater.
For closet installation, clearance is 6 inches (152 mm from
the front of the water heater.
Outdoor models:
RUS65e, RUS75e
Top of Heater
Back of Heater
Front (panel)
Front (exhaust)
Sides of Heater
Ground/Bottom
The clearance for servicing is 24 inches in front of the
water heater.
10
to Non-
Combustibles
inches (mm)
6 * (152) 2 *(51)
0 (zero) 0 (zero)
6 (152) 6 (152)
2 (51) 1/2 (13)
12 (305) 12 (305)
0 (zero) 0 (zero)
to Non-
to Combustibles
Combustibles
inches (mm)
inches (mm)
12 (305) 2 (51)
0 (zero) 0 (zero)
24 (610) 0 (zero)
24 (610) 24 (610)
6 (152) 1/8 (3.2)
12 (305) 2 (51)

Freeze Protection

Make sure that in case of freezing weather the water
heater and its water lines are protected to prevent
freezing. Damage due to freezing is not covered by
the warranty.
With electrical power and gas supplied, the water
heater will not freeze when the outside air
temperature is as cold as –22°F (-30°C) for indoor
models or is as cold as –4°F (-20°C) for outdoor
models, when protected from direct wind exposure.
Because of the "wind-chill" effect, any wind or
circulation of the air on the unit will reduce its ability
to protect itself from freezing.
In the event of a power failure and/or gas
interruption at temperatures below freezing the
water heater should be drained of all water to
prevent freezing damage. In addition, drain the
condensate trap and drain line.
Loss of freeze protection may result in water damage
from a burst heat exchanger or water lines.
The unit may be drained manually. However, it is
highly recommended to:

drain down solenoid valves be purchased and
installed that will automatically drain the unit if
power is lost. These are available in a kit,
104000059. (The condensate trap is not affected
by the auto drain down solenoid valves and will
have to be manually drained.)

a surge protector with terminals be purchased
and installed which allows the solenoid valves to
operate if the unit is disabled due to a diagnostic
code. This is available as 104000057.
In addition, the solenoid valves should be connected
electrically to a surge protector with terminals. This
allows the solenoid valves to operate if the water
heater is disabled due to a diagnostic code.
The freeze protection features of the water heater
will not prevent the external piping from freezing. It
is recommended that hot and cold water pipes be
insulated. Pipe cover enclosures may be packed with
insulation for added freeze protection.
It is recommended that the condensate trap drain line
be insulated. A frozen condensate trap results in a
diagnostic code 25.
KCM Series Manual