Rinnai RU80i - Isolation Valves and Pressure Relief Valve; Isolation Valves Installation Instructions; Pressure Relief Valve Installation Instructions; Pressure Relief Valve Maintenance

KB Series Manual 39
Isolaon Valves and Pressure Relief Valve
The isolaon valves provide the ability to isolate the
water heater from the structure’s plumbing and allow
quick access to ush the heat exchanger. Check with
local codes to determine if a pressure and
temperature relief valve is required. The included
valves meet American Naonal Standard (ANSI
Z21.10.3) / Canadian Standard (CSA 4.3) and are
ANSI/NSF 61 approved for potable water.

1. Wrap the ends of the threaded water inlet &
outlet on the tankless water heater, as well as
the threaded end of the approved pressure relief
valve with a minimum of 5 wraps of Teon®
tape.
2. Screw the pressure relief valve into the 3/4”
threads opposite the wing handle on the HOT
water service valve. (RED drain handle) (see
Pressure Relief Valve Secon for proper
installaon requirements)
3. Loosen the 3/4” union nut on the HOT water
valve and connect to the HOT water outlet on
the tankless water heater. If nut is removed,
ensure that you realign the tailpiece accurately
to the valve and that the black washer is
posioned such that the raised metal edge of
the valve is inside the washer.
4. Align the direcon of the HOT water drain to the
desired posion.
5. Tighten the union assembly to the HOT water
valve using approximately 15 foot lbs of torque.
6. Repeat steps 3-5 for the COLD water valve.
(BLUE drain handle) for connecon to the COLD
water inlet on the tankless water heater.
7. Connect the INLET on the COLD water valve to
the MAIN SOURCE of the water supply.
8. Connect the OUTLET on the HOT water valve to
the HOT WATER plumbing system.
9. Ensure that both drain valve lever handles are in
the closed posion (perpendicular to the drain
poron of the body).

The PRV must be connected by the threaded
connecon opposite the wing handle on the hot
water valve (designated by the RED drain handle) or
the threaded connecon on the side of the relocaon
ng above the hot water valve. Installaon must
maintain a ¾” port size with no shut o valve or line
restricon in-between the appliance and the PRV. The
discharge line from the PRV should pitch downward
and terminate 6” above drains where discharge will
be clearly visible. The discharge end of the line shall
be plain (unthreaded) and a minimum of ¾” in
diameter. The discharge line material must be
suitable for water at least 180° Fahrenheit and can be
no more than 30 feet in length and contain no more
than 4 elbows or bends. No valve of any type may be
installed in the discharge line of the pressure relief
valve.

For proper care of this approved pressure relief valve,
it is recommended that the valve is manually
operated once a year. In doing so, it will be necessary
totake precauons with regard to the discharge of
potenally scalding hot water under pressure. Ensure
discharge has a place to ow. Contact with your body
or other property may cause damage or harm.
Please note that only the PRV in this package is
cered by CSA Internaonal as an approved item.
 Pressure Relief Valve (PRV)
 PRV Discharge Outlet
 Hot Ball Valve Drain Handle
 Cold Ball Valve Drain Handle



