Navien NPE-180A2 Installation Manual page 37

3.4.6 Connecting a Pressure Relief Valve
WARNING
ONLY licensed professionals should install the
●
pressure relief valve.
ALWAYS follow all instructions and guidelines
●
when installing the pressure relief valve.
Improper installation of the pressure relief
valve may result in death, serious injury, or
property damage.
The pressure relief valve is not supplied, but
●
is required.
To complete the installation of the water heater,
you must install an approved
PSI pressure relief valve on the hot water outlet. The
water heater has a built-in high temperature shut off
switch, so install a "pressure only" relief valve. This
valve is not supplied, but is required. The following
examples are approved for use with the water
heater:
Wilkins P-1000A (Zurn Industries)
●
Conbraco 17-402-04
●
Watts Industries 3L (M7)
●
Cash Acme FWL-2, / in.
3
●
4
The pressure relief valve should be
Note
placed as close to the water heater
as possible. No other valve should be
placed between the pressure relief
valve and the water heater.
Pressure
Relief Valve
Shut-off Valve
Gas Hot Water
WARNING
To prevent scalding, burns and water damage,
always route the discharge line to a safe location.
/ in. maximum 150
3
4
Cold Water
When installing the valve, follow these guidelines:
Ensure that the discharge capacity of the pressure
●
relief valve is equal to or greater than the
maximum pressure rating of the water heater.
Ensure that the maximum BTU/H rating on the
●
pressure relief valve is equal to or greater than the
maximum input BTU/H rating of the water heater.
Direct the discharge piping of the pressure relief
●
valve so that hot water will not splash on anyone
or any nearby equipment.
Attach the discharge line to the pressure relief
●
valve with approved materials and run the end of
the line to within 6 - 12 in. (150 - 300 mm) of the
floor drain, making discharge clearly visible.
Ensure that the discharge line will allow free and
●
complete drainage without restriction. Do not
install a reducing coupling or other restriction on
the discharge line.
Do not direct the discharge line to a location
●
where freezing could occur.
Ensure that the discharge line is not plugged or
●
obstructed.
After filling and pressurizing the system, test
●
the relief valve operation by lifting the lever. If
the valve fails to operate correctly, immediately
replace the relief valve.
If the relief valve discharges periodically, this may
●
be due to thermal expansion in a closed water
supply system. Contact the water supplier or
local plumbing inspector on how to correct this
situation. Do not plug the relief valve.
WARNING
To prevent serious injury or death, the
●
pressure relief valve should be checked at
least once every three years by manually
operating the relief valve.
Before manually operating the valve, check
●
the discharge line and discharge location to
ensure you or others will not come in contact
with hot water. Hot water can cause burns
and may result in serious injury or property
damage.
Installing the Water Heater 37