12
Troubleshooting
120 volt potential exposure. Use caution making
voltage checks to avoid personal injury.
WARNING
Use caution not to damage connectors when
making voltage measurements or jumping terminals
CAUTION
From previous page.
Does combustion
blower operate?
Error code #67 on display. Measure voltage
between black and white wires, of the 3 wire
harness, at the blower (make sure the
control display shows “heating” in the status
mode, if not increase the setpoint). Is there
110-120 VAC?
Replace power cord/blower harness if
display shows “heating” and no voltage
is present to the blower.
Check that the 5 wire blower
modulation harness is plugged
in to the blower
Plug in the wire harness. (Note: If
this harness is unplugged blower
will run constantly.)
Can sparking be
seen/heard at the spark
rod to the burner?
Remove high voltage wire connected at
the spark rod and hold approximately ¼”
from metal ground with insulated pliers
during the ignition cycle (3 second spark
trial period). Is there spark to ground?
Check resistance of high voltage
cable. Resistance should be 0-1
ohms. If resistance is high, replace
spark cable. If spark cable is good,
replace control board.
Check continuity of spark rod and spark
rod gap to burner. (see section “Spark
Rod Gap Adjustment.”
Does main burner light?
Error code #110 on display.
See main burner lights, no
flame signal in section
“Combustion System Testing
and Replacement.”
(See “Combustion System
Testing and Replacement”).
Does burner continue until
thermostat set point is
reached? See setting
display in Service Mode
and displaying
temperature sensors.
Does blower post-purge for
30 seconds?
System okay
Check to see if control display shows any other error codes
(pressure switch, vent safety switch, or high limit). If so, refer to
the appropriate section for testing and replacement.
Replace
Blower
Replace
Control
Module
Measure voltage
between yellow and
green wires. Is there
17-30 VDC?
N
N
N
N
N
N
N
N
Y
Y
Y
Y
Y
Y
Y
Y
Y
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