Troubleshooting; Solving Basic Problems - Navien NFC-250/200H User's Information Manual

5. Troubleshooting

5.1 Solving Basic Problems

If you experience a problem with the boiler, 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 boiler may resolve
the issue. To reset the boiler, press the Back button
( ) on the front panel.
If resetting the boiler 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.
The water from the
hot water faucet is
not hot enough.
The water from the
hot water faucet is
too hot.
Space heating side
malfunction
Possible Cause(s)
Is the cold water inlet filter clean?
Is an error code displayed on the
front panel?
Is the boiler frozen?
Is the hot water faucet open wide
of water per minute (GPM)
through the boiler?
Is an error code displayed on the
front panel?
Is the set temperature too low?
Is the set temperature set too high?
Is the setting temperature too low?
Is there power to the system, or is
the system in stand by?
Is the system running for domestic
hot water (DHW)?
Is the filter on the heating side
restricted?
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 24.
If an error code is displayed, refer to
"5.2 Understanding Error Codes" on page 24.
Check the boiler's temperature setting. Refer
to "3.2 Adjusting the System Temperatures"
on page 10.
Check for cross piping between the cold and
hot water lines.
Check the boiler's temperature setting. See
"3.2 Adjusting the System Temperatures" on
page 10.
Check the boiler's temperature setting. See
"3.2 Adjusting the System Temperatures" on
page 10.
Make sure the power is on, and plugged into
the outlet with the correct voltage. Press
the Power button ( ) and raise the setting
temperature. Make sure the boiler is turned on.
When the unit is heating for DHW, the heating
side does not work.
Clean out filters that belong to the heating
side.
Troubleshooting 23