352Error - Navien NFC-175 Service Manual

5.2.19 352Error

Error conditions and Check Items
Error
E352
High water pressure
Check items
Check method
If the error occurs during combustion, stop the combustion and perform post-purge 1 and switch to Safety Shut-down (gas valve and
●
ignition transformer locked).
If the error occurs while the combustion is stopped, keep the combustion stopped and switch to Safety Shut-down (gas valve and ignition
●
transformer locked).
Keep all pumps (the boiler, zone pumps) stopped (other than when running Pump Test Mode).
●
However, when setting the zone valve system, ensure that all pumps (the boiler, system, hot water) and the zone valves are stopped (other
●
than when running Pump Test Mode).
Error releasing condition: The high water pressure error is automatically cleared when the water pressure has been detected as lower than
●
[the standard water pressure – 13 psi (0.9 bar)] consecutively for more than three seconds.
104 NFC Service Manual
If the automatic water pressure sensor detects that the water pressure is higher than [the
standard water pressure] for more than three seconds consecutively, the system stops
operation of the boiler and a high water pressure error message ("352, " automatically cleared) is
displayed.
However, if a malfunction occurs when the water pressure sensor is in the Open or Short status,
the high water pressure error will not be determined.
The standard water pressure over high water pressure can be set on the panel, and the setting
method is shown as below.
Parameter Setting No.
High Sys Pressure (16)
1. Check if the cold water pipe input water pressure sensor is wet due to any reason, including
leakage.
2. Check the controller.
Is the cold water fill valve
or the pressure safety valve
malfunctioning?
No
Is the water pressure sensor
normal?
Yes
1. Check connecter
(#4,#5 and #6 of CNG1)
Description
Setting range
40-80 psi (2.7-5.5 bar)
Yes
Replace the malfunctioning
component
No
Replace the water pressure sensor
Default
50 psi (3.4 bar)
Version 1.0