Checklist For Plumbing; Installation Of Gas Supply - Rinnai RUC80i Installation And Operation Manual

Connect Water Heater to Water Supply
Water connections to the tankless water heater
should follow all state and local plumbing codes.
If this is a standard installation, refer to the Piping
Diagram for Basic Installation.
1. Plumb water supply to the tankless water heater
on the 3/4" MNPT connection at the bottom of
the unit marked "Water Inlet", which is the cold
water supply.
2. Plumb the building hot water supply to the 3/4"
MSPT connection marked "Water Outlet", which
is the hot water supply.
If a pipe cover will be installed, make sure water lines
to the water heater fit.

Checklist for Plumbing

□
Purge the water line of all debris and air by
closing the hot isolation valve and opening the
cold isolation valve and its drain. Debris will
damage the water heater. Use a bucket or hose
if necessary.
□
Ensure that hot and cold water lines are not
crossed to the unit and are leak free.
□
Ensure that a pressure relief valve is installed with
a rating that exceeds the BTU input of the water
heater model. Refer to the rating plate on the
side of the water heater for BTU input.
□
Clean the inlet water filter by closing the cold and
hot water inlet isolation (shut-off) valves. Put a
bucket under the filter at the bottom of the water
heater to catch any water that is contained inside
the unit. Unscrew the water filter. Rinse the
filter to remove any debris. Install the filter and
open the isolation valves.
□
Check for proper water pressure to the water
heater. Minimum water pressure is 50 psi. Rinnai
recommends 60-80 psi for maximum
performance.
□
Ensure any issues regarding water quality have
been properly addressed.

Installation of Gas Supply

WARNING
1. A licensed professional must install the gas
supply.
2. Turn off 120v power supply.
3. Turn off the gas.
4. Gas is flammable. Do not smoke or provide other
ignition sources while working with gas.
5. Do not turn on the water heater or gas until all
fumes are gone.
General Instructions
MUST DO

A manual gas control valve must be placed in the
gas supply line to the water heater. A union can be
used on the connection above the shut off valve
for the future servicing or disconnection of the
unit.

Check the type of gas and the gas inlet pressure
before connecting the water heater. If the water
heater is not of the gas type that the building is
supplied with, DO NOT connect the water heater.
Contact the dealer for the proper unit to match the
gas type.

Check the gas supply pressure immediately
upstream at a location provided by the gas
company. Supplied gas pressure must be within
the limits shown in the Specifications section of
this manual with all gas appliances operating.

Before placing the appliance in operation, all joints
including the heater must be checked for gas
tightness by means of leak detector solution, soap
and water, or an equivalent nonflammable
solution, as applicable. (Since some leak test
solutions, including soap and water, may cause
corrosion or stress cracking, the piping shall be
rinsed with water after testing, unless it has been
determined that the leak test solution is non-
corrosive.)

Use approved connectors to connect the unit to
the gas line. Purge the gas line of any debris
before connection to the water heater.
KBD Series Manual 41