White-Rodgers Self Diagnostic Features - American Standard 50A65-475 Manual

White-Rodgers Self Diagnostic Features

The integrated furnace control tests for internal and
external faults before allowing a heating sequence to
begin. The external check includes all safety devices,
making certain that they are in their proper normally
open or normally closed position. If a fault is detected
by the control, it will immediately enter into a fault
mode and flash the LED light according to the fault
detected (see LED Flash Rate table below). The control
will remain in the fault mode until the problem is
corrected. Once the fault is cleared, the control will
start the heating sequence as long as the call for heat
still exists.
The control has an expanded diagnostic feature that
monitors system performance. If a fault is detected
during operation, the control will de-energize the gas
valve and flash the diagnostic LED according to the
fault detected.
The control will automatically reset a lock-out due to
loss of flame in one hour.
LED Flash Rates
Normal Operation
• The LED will flash for one second at power up.
• The LED will flash "FAST" , 1⁄4 second "ON" and
1⁄4 second "OFF" , during a call for heat.
Fault Diagnostic
LED Flash
Slow Flash
Fast Flash
Continuous ON
2 Flashes
3 Flashes
4 Flashes
5 Flashes
6 Flashes
7 Flashes
8 Flashes
9 Flashes
50A61-605 part #CNT02536 will only show the first seven flash codes.
Indicates
Normal Stand By.
Normal with a Call for Heat.
Internal Fault in the IFC.
System Lockout – No Flame. Total of three tries. Automatic reset in one hour.
Pressure Switch Error. (Fault may be caused by a vent problem or a wiring
connection in the switch circuit.) On two speed furnaces, if there is a high heat
pressure switch fault, the IFC will not lock out. It will go back to low heat, cancel
the three flash indication for ten minutes and again try high heat.
Thermal Protection Device Open.
Flame Being Sensed with Gas Valve De-energized (Stuck Open). Vent Motor and
Indoor Blower will be Energized.
No Ground or Power Leads to Furnace Reversed, or Line Voltage Too Low.
20 VAC at Gas Valve with No Call for Heat or if No Flame is Present;
Keep Vent Motor On.
Low Flame Sense Signal.
Ignitor Fault or Improper Ground or Low Voltage.
31
• The LED will flash "SLOW" , 1⁄4 second "ON" and 3⁄4
second "OFF" , with system in stand-by (power on).
Note: The LED will flash "ON" for approximately 1⁄4
second, then "OFF" for approximately 1⁄4 second.
The pause between groups of flashes is approximately
two seconds.
Y1
CR
R58
CR18
C6
CR19
C13
R66
CR23
DS1
R78
C12
R29
U3
R54
R85
R88
R79
R55
R89
R98
R92
C17
R91
CNT02536
C5
C7
STATUS LED
LIGHT (RED)
D14
RPM LED
(GREEN)
C14
W3
R63
C9
RPM
R56
U2
R11 DS6
C14
C24
VR1 R22
C3
R3
R4
C21
C2
R61
R2
D11 D18
R59
1
2
3
4
5