Unit Control Board Flash Codes - York SUNLINE MagnaDRY WR300 Installation Manual

4. Make sure that the ground connections at the pilot
burner, gas valve and ignitor control are intact.
Check the high tension wire for good electrical con-
nection. If all are intact, replace the ignitor module.
The pilot burner lights and the spark stops but the main
burners do not light.
1. Check electrical connections between the ignitor
control and the gas valve. If intact, check for 24
volts across terminals "MV" and "COMMON" termi-
nals. If no voltage detected, replace ignitor control.
If voltage is present, replace gas valve.
Furnace lights with roll-out or one burner has delayed
ignition.
1. Make sure that the carryover is aligned properly
with the flame sensor as described in "PILOT
CHECKOUT" page 64.
Main burners light but exhibit erratic flame characteris-
tics.
1. Adjust air shutters as described in "BURNER AIR
SHUTTER ADJUSTMENT" page 64.
2. Check the main burner orifices for obstruction and
alignment. Removal procedure is described in
BURNER INSTRUCTIONS page 64. Clean or
replace burner orifices and burners as needed.
Johnson Controls Unitary Products

UNIT CONTROL BOARD FLASH CODES

Various flash codes are utilized by the unit control
board (UCB) to aid in troubleshooting. Flash codes are
distinguished by the short on and off cycle used
(approximately 200ms on and 200ms off). To show
normal operation, the control board flashes a 1 second
on, 1 second off "heartbeat" during normal operation.
This is to verify that the UCB is functioning correctly.
Do not confuse this with an error flash code. To prevent
confusion, a 1-flash, flash code is not used.
Alarm condition codes are flashed on the UCB lower
left Red LED, See Figure 30. While the alarm code is
being flashed, it will also be shown by the other LEDs:
lit continuously while the alarm is being flashed. The
total of the continuously lit LEDs equates to the number
of flashes, and is shown in the table. Pressing and
releasing the LAST ERROR button on the UCB can
check the alarm history. The UCB will cycle through the
last five (5) alarms, most recent to oldest, separating
each alarm flash code by approximately 2 seconds. In
all cases, a flashing Green LED will be used to indicate
non-alarm condition.
In some cases, it may be necessary to "zero" the
ASCD for the compressors in order to perform trouble-
shooting. To reset all ASCDs for one cycle, press and
release the UCB TEST/ RESET button once.
Flash codes that do and do not represent alarms are
listed in Table 36.
284813-YIM-C-1008
73