Troubleshooting; Solving Basic Problems - Navien NPN-160U User's Information Manual

5. Troubleshooting

5.1 Solving Basic Problems

If you experience a problem with the
water heater, refer to the following chart
for possible remedies. Error codes that
appear on the front panel display are
explained in the following section.
For minor problems, resetting the water
heater may resolve the issue. To reset the
water heater, press the Reset button on
the front panel or the OK button on the
remote controller.
If resetting the water heater and attempting the remedies suggested below do not resolve the problem, contact
an authorized technician, a licensed professional, or Technical Support at 1-800-519-8794 for service instructions.
Problem
No water comes out
when the hot water tap
is opened.
The water from the hot
water faucet is cold or
turns cold and stays
cold.
It takes too long for
hot water to reach the
fixtures.
The water is not hot
enough.
The water is too hot.
Possible Cause(s)
Is the cold water inlet filter
clean?
Is an error code displayed on
the front panel?
Is the water heater frozen?
Is the cold water inlet filter
clean?
Is the hot water faucet open
wide enough draw at least
0.5 gallons of water per
minute (GPM) through the
water heater?
Is an error code displayed on
the front panel?
If there is an external
recirculation system installed,
is there a check valve on the
recirculation return line?
Are you using the external
recirculation mode?
Is the set temperature too low?
Is the set temperature set too
high?
[Indoor Models]
What to do
Ensure that the shut–off valves on the hot
and cold pipes are open.
If an error code is displayed, refer to
"5.2 Understanding Error Codes" on
page 22.
Clean the cold water inlet filter. See "4.4
Cleaning the Inlet Water Filter" on page 19.
Open the hot water faucet completely.
If an error code is displayed, refer to
"5.2 Understanding Error Codes" on
page 22.
Have a contractor install a recirculation return
line from the furthest faucet back to the water
heater.
Check the water heater's temperature
setting. Refer to "3.2 Adjusting the Water
Temperature" on page 11.
Check for cross plumbing between the cold
and hot water lines.
Check the water heater's temperature setting.
See "3.2 Adjusting the Water Temperature" on
page 11.
[Outdoor Models with
Remote Controller]
Troubleshooting 21