80
Fault Isolation
2583701_C_EN_1812_Nortec-GS_OM
Nortec GS
Code
Message
Probable Cause
Corrective Action(s)
Warning
Fault
W149
E149
AP Open Warn
The air proving switch identified has opened while the unit was operating
or during blower start-up. The unit will interrupt operation and retry three
times. After a third attempt a fault message is generated. The unit is unsafe
to operate with this fault condition. Fix the problem before restarting the
unit.
Blockage in the air intake vent or air
intake terminal.
– Visually inspect the air intake
vent and air intake terminal for
blockages.
Pressure tubes not connected, or
loose wiring.
– Check the pressure tube con
-
nections are attached securely.
– Check the wiring between the air
proving switch(es) and connec
-
ctor J2 on the driver board. With
demand off and the blower not
operating, check for 24 VAC at
pins 1 and 2 on connector J2.
Defective air proving switch.
– Check that the air proving switch
remains closed during operation
of the blower. Check for suction
in the pressure tubes. If the air
proving switch does not close, it
may be defective and must be
replaced.
Exhaust condensate removal (on CS/
NX model) may be blocked.
– Check for blockages in the ex
-
haust drain line in the unit.
7.5
Resetting Fault Status
With the exception of the over-temperature fault (see below), the following procedure should be used to
reset all other fault conditions including the ignition control module safety lockout.
Reset the "Fault" status as follows:
1. Correct the cause of the problem.
2. Set the On/Off button to the Off position.
3. Wait approximately for 5 seconds, then set the On/Off button to the On position.
If the alarm condition has been eliminated, the fault message is automatically reset; otherwise the
fault message reappears after a short while.
Resetting Over-Temperature Fault
Reset the over-temperature "Fault" status as follows:
1. Correct the cause of the problem.
2. Wait for the unit to cool down.
3. Press the reset button on the over-temperture switch.
4. Set the on/off button to the Off position. Wait for approximately 5 seconds.
5. Set the on/off button to the On position. If the alarm condition has been eliminated, the fault message
is automatically reset. Otherwise, the fault message reappears after a short while.
