Troubleshooting - Reznor UDBP Installation & Operation Manual

10.0 Maintenance and Service (cont'd)

10.3 Troubleshooting

Check the Lights on
the DSI Integrated
Control Module
(Circuit Board)
DSI Integrated Control Module (Circuit
Board) Trial Troubleshooting Flowchart
Is there minimum
YES
flame current at the
Is there
YES Replace control
minimum flame current
at the control
module?
NO
Check connections to flame
sensor and/or moisture in the
burner assembly.
Form I-UDB, P/N 202658 R10, Page 40
The integrated circuit board monitors the operation of the heater and includes two
LED signal lights that indicate normal operation and various abnormal conditions. If
the heater fails to operate properly, check this signal to determine the cause and/or
to eliminate certain causes. LED is visible through viewport on Model UDBS. Remove
access panel on Model UDBP. See operating sequence in Paragraph 9.
Do not attempt to repair the DSI integrated control module (circuit board); the only field
replaceable component is the fuse.
IMPORTANT: When using a multimeter to troubleshoot the 24 volt circuit, place the
meter'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 due to the ignition control board's fault mode monitoring
circuits.
Control Status - Green LED Codes
Steady ON Normal Operation, No call for heat
Fast Flash . Normal Operation, Call for heat
1 Flash ...... System Lockout, Failed to detect or sustain flame
2 Flashes .. Pressure Switch Did Not Close within 30 Seconds of Venter Motor
3 Flashes .. High Limit or Flame Rollout Switch Open
4 Flashes ....Pressure Switch is Closed Before Venter Motor is Energized
Steady OFF Blown fuse, No Power, or Defective Board
Flame Status - Yellow LED Codes
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)
YES Does gas
ignite?
Is the flame
NO
sensor corroded?
flame sensor?
NO
Is the sensor
located in flame
module.
correctly?
NO
Reposition
flame sensor.
YES
Check gas pressure
and supply voltage.
If either are low,
correct and repeat
startup.
Trial for Ignition
Call for Heat
Is there a
YES
spark across gap at
ignitor?
NO
YES
Clean flame
sensor.
YES Replace flame
sesnsor.
YES Is gas
flowing?
Is the ignitor
Replace gas
position correct in the
valve.
gas flow?
NO
Check wiring and
Reposition
connections to
spark ignitor.
gas valve.
NO
Is there Check high
YES
spark voltage at voltage wire
control? continuity.
NO
Replace
YES
Is there 24V P1-2
control
to power control?
module.
NO
Check wiring
and/or 24VAC
transformer output.
NO
Is there
YES
24VAC at the gas
valve?
NO
Is there 24VAC
YES from gas valve output on
control module to
chassis?
Replace
NO ignition
control
module.