Reznor LDAP, Installation Operation & Maintenance

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46 LDAP-IOM (01-22) 207733-A
—Continued Table 19. General Troubleshooting
Symptom Probable Cause Remedy
No heat
(heater
operating)
1 . Incorrect valve outlet pressure or orifice Check valve outlet pressure (refer to unit rating plate for manifold pressure)
2 . Cycling on limit control Check air throughput
3 . Improper thermostat location or
adjustment
Refer to thermostat manufacturer's instructions
Fan or
venter
motor will
not run
1 . Circuit open Check wiring and connections
2 . Defective integrated circuit board Replace board
3 . Defective motor Replace motor
Fan or
venter
motor turns
ON and
OFF while
burner is
operating
1 . Motor overload device cycling ON and
OFF
Check motor load against motor rating plate—replace motor if needed
Fan or
venter
motor cuts
out on
overload
1 . Low or high voltage supply Correct electric supply
2 . Defective motor Replace motor
3 . Poor airflow Clean motor, fan, fan guard, filter, and coils
4 . Defective bearing or lubrication Lubricate bearings (motor permitting) or replace motor
TROUBLESHOOTING—CONTINUED
General Troubleshooting—Continued
Unit Troubleshooting Using DSI Control Module
The DSI control module (refer to Circuit Board (DSI Control Module) section) may be used to troubleshoot the unit .
The control module monitors monitors the operation of the heater and includes two indicator LEDs (green indicates
control status, yellow indicates flame status) that indicate normal operation and various abnormal conditions (refer to
Table 20 ) . If the heater fails to operate properly, check the LEDs to determine the cause and/or to eliminate certain
causes . See Figure 23 for a flowchart for troubleshooting the unit using the DSI control module .
NOTES:
• If troubleshooting indicates that repair of the DSI control module is required, note that its only
replaceable part is the fuse (see
Figure 14
), which is a type ATC or ATO 3A fuse, color code violet
(PN 201685).
• IMPORTANT: When using a multimeter to troubleshoot the 24V circuit, place the multimeter’s test
leads into the 5- or 9-pin connectors located on the ignition control. Do not remove connectors
or terminals from the electrical components. Doing so can result in misinterpreted readings
caused by the control module’s fault mode monitoring circuits.
Table 20. Circuit Board (DSI Control Module) Display Codes
LED Status Indication
Green
Steady ON Normal operation—no call for heat
Fast flash Normal operation—call for heat
One flash System lockout—failed to detect or sustain flame
Two flashes
Heat section or flue collection box section pressure switch does not close within 30
seconds of venter being energized
Three flashes Auto-reset or manual-reset high temperature limit switch is open
Four flashes
Heat section or flue collection box section pressure switch is closed before venter is
energized
Steady OFF Blown fuse, no power, or defective board
Yellow
Steady ON Flame is sensed
Slow flash Weak flame—current below 1 .0 microamps ±50%
Fast flash Undesired flame—valve open and no call for heat