Page 18
The ignition control is equipped with two LED lights for troubleshooting. The diagnostic codes are listed below in table 4.
TABLE 4
DIAGNOSTIC CODES
Make sure to Identify LED’S Correctly.
Refer to figures 5 and 8 for control board layout.
LED #1
DS #1
AN #1
LED #2
DS #2
AN #2
DESCRIPTION
SIMULTANEOUS
SLOW FLASH
SIMULTANEOUS
SLOW FLASH
Power on − Normal operation.
Also signaled during cooling and continuous fan.
SIMULTANEOUS
FAST FLASH
SIMULTANEOUS
FAST FLASH
Normal operation − signaled when heating demand initiated at thermostat.
SLOW FLASH
ON
Primary or secondary limit switch open. Limit must close within 3 minutes or unit
goes into 1 hour Watchguard.
OFF
SLOW FLASH
Prove switch open.
OR: Blocked inlet/exhaust vent;
OR: Prove switch closed prior to activation of combustion air inducer.
ALTERNATING
SLOW FLASH
ALTERNATING
SLOW FLASH
Watchguard −− burners failed to ignite.
SLOW FLASH
OFF
Flame sensed without gas valve energized.
ON
SLOW FLASH
Rollout switch open. OR: 24V pin connector improperly attached.
ON
ON
ON
OFF
Circuit board failure or control wired incorrectly.
OFF
ON
y
FAST FLASH
SLOW FLASH
Main power polarity reversed. Switch line and neutral.
SLOW FLASH
FAST FLASH
Low flame signal. See Table 15 for flame sense.
ALTERNATING
FAST FLASH
ALTERNATING
FAST FLASH
The following conditions are sensed
Improper main ground (Control 10M93, 57L84) during ignitor warm up period
ONLY, improper main ground continuously (Control 78M47 & 100973−01)
OR: Broken ignitor (Control 10M93, 57L84)
OR: Open ignitor circuit (Control 78M47 & 100973−01)
OR: Line voltage below 75V (Control 10M93, 57L84) 90V (Control 78M47 &
100973−01)
NOTE − Slow flash rate equals 1 Hz (one flash per second). Fast flash rate equals 3 Hz (three flashes per second).
FIGURE 7
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉ
ÉÉ
DEMAND
CAI
GAS VALVE
15
ON
OFF
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉ
38
ÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉ
IGNITOR
34
1
Pre −Purge
Ignitor Warm−up
Trial for
Ignition
Post
Purge
5 SEC
80
*Blower on time will be 45 seconds after gas valve is energized. Blower off time will depend on OFF TIME" Setting.
INDOOR BLOWER
ÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉ
Blower On"
Delay
IGNITION CONTROL 10M93 & 56L84** & 78M47*** & 100973−01
**Ignitor on control 57L84 will energize for the first second ONLY of the 4 second ignition trial
***ignitor on control 78M47 & 100973−01 will energize the first three seconds ONLY of the 4 second ignition trial
