Wayne SC80, User Manual, Page: 19 / 29

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Once the flame is established, assure that the flame current is above the minimum specified. If not, assure that the
system has the proper input voltage. During service, a scale may build up on the flame sensing rod, which may also
reduce flame current readings.
DO NOT USE LIQUIDS TO CLEAN. Use steel wool or emery cloth to clean.
Once the flame is has been established and the system is in its heat cycle, occasional sparking may occur. This is
common in some installations and is not significant. Sparking will not damage the ignitor.
Table 6: Service Hints
What’s Wrong Why What To Do

Lockout occurs 3-10 seconds
after ignition.

Reverse polarity.

System improperly grounded.

Gas pressure too high, causing
flame to lift off burner.

See Input Polarity (See 1)

See Improperly Grounding (See 2)

Check to ensure input pressure as
specified on manufacturer’s data
plate.

See Flame Current (See 6)

Flame not established. Arcing to
ground.

No spark.

Arcing other than across gap.

Sensor probe incorrectly
positioned in flame pattern. Spark
gap too small. Spark too large.
Corroded connector.

Cracked or dirty insulator.

See Inoperative High Voltage
(See 3a)

Weak spark.

Broken high voltage lead. High
voltage lead too close to metal
surface. Valve malfunction.
Electrode improperly placed.

See Valve Malfunction (See 4)

See Electrode Placement (See 5)

See Flame Current (See 6)

Check to ensure that manifold
pressure meets manufacturer’s
specifications

No flame.

Low flame current and/or
nuisance lockouts.

Flame current falls below 0.1 µA.

Low gas pressure.
COMPONENT TROUBLESHOOTING AND DIAGNOSIS
24 VOLT TRANSFORMER MALFUNCTION
The 24 volt transformer has a 120 volt primary side with a 24 volt secondary circuit. To check the transformer,
simply apply 120 volts to the black and white leads. If the transformer is working correctly, 24 volts will be present
across the two yellow leads. If the multimeter does not register 24 volts then the transformer needs to be
replaced. The transformer will not function unless 120 volts are present across L1 and neutral.
COMBUSTION FAN ENDSWITCH
The 120 volt motor is equipped with a centrifugal endswitch. The purpose of the endswitch is to ensure that the
combustion fan motor has reached the proper operating rpm which is generally about 3400 rpm. If the endswitch
fails to close then the 24 volt circuit to the gas primary is interrupted and the gas valve will not open. If the blower
motor has 120 volts applied but is not rotating then the motor assembly must be replaced. Lastly if the motor is
not rotating, the centrifugal switch will not make and 24 volts will not be present at the gas primary control.
IGNITER ROD
The igniter rod is responsible for conveying the spark to a grounding rod in an appropriate location to ignite the
gas and air mix. The igniter rod gap should be 1/8”, larger gaps will create ignition problems. If the igniter rod is
cracked, sparking sound will be heard inside the burner air tube but ignition will not occur and lockout will occur.