Rinnai Demand Duo R Series Installation And Operation Manual page 37

Water connections to the water heater should
follow all state and local plumbing codes. If this is
a standard installation, refer to section "7.4 Piping
Diagram for Basic Installation."
1. Use of this layout should provide a trouble-
free installation for the life of the water heater.
Before making the plumbing connections,
locate the COLD water inlet and the HOT
water outlet.
•
The COLD water inlet is a 1.5 in. MNPT
fitting on the lower portion of the tank
below the tankless unit. Install a shut-off
valve close to the water heater in the cold
water line.
•
The HOT water outlet is a 1.5 in. MNPT
fitting located at the top of the tank. It is
recommended that unions be installed in
the cold and hot water lines so that the
water heater can be easily disconnected,
if servicing is required.
2. When assembling the hot and cold piping,
use a good, food grade pipe joint compound,
and ensure all fittings are tight. It is impera-
tive that open flame is not applied to the inlet
and outlet fittings, as heat will damage or de-
stroy the plastic lined fittings. This will result
in premature failure of the fittings, which
is not covered by the warranty.
DO NOT OPERATE THIS WATER HEATER
UNLESS IT IS COMPLETELY FULL OF
WATER. To prevent damage to the water heater,
all air must be relieved from the system and a hot
water fixture must be flowing water before the
water heater is plugged in and turned on. To
ensure safe and effective operation of the water
heater, use the following filling procedure. To fill
the water heater:
Demand Duo™ R-Series Installation and Operation Manual
1. Ensure the drain valve located at the bottom
of the tank is closed.
2. Open the nearest hot water fixture in the
plumbing system.
3. Open the cold water supply valve to the water
heater.
4. Keep the hot water fixture open until the tank
is filled and constant flow is obtained at the
fixture.
5. Check water heater connections and
plumbing system for damage or leaks. Repair
if needed.
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
below the tankless water heater. 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.
Ensure any issues regarding water quality
□
have been properly addressed.
WARNING
DO NOT OPERATE THIS WATER HEATER UN-
LESS IT IS COMPLETELY FULL OF WATER.
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