Surelight Board 100870 - Lennox G61MPV Service Manual

B−SureLight Board 100870
Two Stage Variable Speed Control Board 100870
UPON INITIAL POWER UP, REMOVE ALL THERMOSTAT DEMANDS TO THE UNIT
PROBLEM: 1 UNIT FAILS TO OPERATE IN THE COOLING, HEATING, OR CONTINUOUS FAN MODE
Flash Code
LED X + Y
1.1
− Diagnostic lights fail to light up.
LED OFF
1.2
Diagnostic light flashes the reverse Diagnostic light flashes the reverse
polarity code.
LED 5 + 4
1.3
− Diagnostic light flash the improper
main ground.
LED 5 + 3
1.4
− Diagnostic light flashes ignitor
circuit fault. circuit fault.
LED 4 + 7
1.5
− Diagnostic light flashes low
line voltage
LED 4 + 8
Possible Cause
1.1.1
Main voltage 120V not supplied to unit.
1.1.2
Miswiring of furnace or improper con-
nections.
1.1.3
Circuit breaker tripped or fails to
close.
1.1.4
Door interlock switch failure.
1.1.5
Transformer Failure.
1.1.6
Failed control board.
1.2.1
120V main power polarity reversed. 120V main power polarity reversed.
1.3.1
Improper ground to the unit.
1.4.1
Open ignitor circuit.
1.4.2
Broken or failed ignitor.
1.5.1
Line voltage is below 90V.
Page 97
Corrective Action / Comments
ACTION 1 − Check 120V main voltage.
Determine cause of main power failure.
ACTION 1 − Check for correct wiring of 120V to
power make up box and transformer.
ACTION 2 − Check 24V wiring to control board.
ACTION 1 − Replace circuit breaker if it is reset
but does not have continuity.
ACTION 2 − If circuit breaker still trips, check for
short.
ACTION 1 − Check that door switch is activated
when door is closed.
ACTION 2 − Check wire connections to switch, re-
place loose connectors.
ACTION 3 − Check continuity of switch in closed
position. Replace if defective.
ACTION 1 − Check that transformer output is
24V. Replace if defective.
ACTION 1 − If all the above items have been
checked, replace board.
ACTION 1 − Check the 120V has line and neutral ACTION 1 − Check the 120V has line and neutral
correctly input into control.
ACTION 2 − Reverse the line and neutral at the
120V field connection. 120V field connection
ACTION 1 − Check that the unit is properly ground.
ACTION 2 − Install a proper main ground to the unit
ACTION 1 − Check for correct wiring and loose
connections in the ignitor circuit. Check mult−plug
connections for correct installation.
ACTION 1 − Unplug ignitor and read resistance
across ignitor. If resistance does not read between
25 and 47 ohms, replace the ignitor.
ACTION 1 − Check that the line voltage is above
90V. Determine cause of voltage drop and supply
correct voltage to the control.