Freeze Protection - Rinnai RU80i Installation And Operation Manual

Unit clearances
to front
to floor/ground
Indoor
to Combustibles
models:
inches (mm)
RU80i, RU98i
Top of Heater 6 * (152)
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.
Outdoor
to Combustibles
models:
inches (mm)
RU80e, RU98e
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 top
to side
to Non-
Combustibles
inches (mm)
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-
Combustibles
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 that the
water heater and its water lines are protected to
prevent freezing. Damage due to freezing is not
covered by the warranty.
Loss of freeze protection may result in water damage
from a burst heat exchanger or water lines.
With electrical power 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 freeze protect.
The unit may be drained manually. However, it is
highly recommended that:

drain down solenoid valves are installed that will
automatically drain the unit if power is lost.
These are available in a kit, 104000059. (The
condensate trap drain plug and water drain plug
are not affected by the auto drain down solenoid
valves and will have to be manually opened.)

a surge protector with terminals is 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 will not prevent the
external piping from freezing. It is recommended that
hot and cold water pipes are 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 drain line
results in diagnostic code 25.
In the event of a power failure 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.
KB Series Manual