KBD Series Manual
39
Isolation Valves and Pressure Relief Valve
(PRV)
The isolation valves provide the ability to isolate the
water heater from the structure’s plumbing and allow
quick access to flush the heat exchanger. Check with
local codes to determine if a pressure and
temperature relief valve is required. The included
valves meet
American National Standard (ANSI
Z21.10.3) / Canadian Standard (CSA 4.3)
and are
ANSI/NSF 61 approved for potable water.
Isolation Valves Installation Instructions:
1. Wrap the ends of the threaded water inlet and
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 Teflon®
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 Section for proper
installation 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
positioned such that the raised metal edge of
the valve is inside the washer.
4. Align the direction of the HOT water drain to the
desired position.
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 connection 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 position (perpendicular to the drain
portion of the body).
Pressure Relief Valve Installation Instructions:
The PRV must be connected to the 3/4” threaded port
on the HOT (RED) water service valve (will be adjacent
to or above the shut off, never below). Installation
must maintain a ¾” port size with no shut off valve or
line restriction 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. No valve
of any type may be installed in the discharge line of
the pressure relief valve.
Pressure Relief Valve Maintenance:
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
to take precautions with regard to the discharge of
potentially scalding hot water under pressure. Ensure
discharge water has a safe place to flow. Contact
may cause property damage and/or bodily harm.
Please note PRV included meets the rating
requirements for use with the tankless water heater.
Should a replacement valve be needed it must be
rated for up to 150 psi and at least the maximum
BTU/hr of the appliance.
A
Pressure Relief Valve (PRV)
B
PRV Discharge Outlet
C
Hot Drain Valve
D
Cold Drain Valve
E
Hot Ball Valve
F
Cold Ball Valve
A
B
C
D
F
E
When unscrewing the UNION FITTING, Be careful not
to lose any washers and/or gaskets that may be
present.
NOTICE
