Frymaster OCF30ATOG Service & Parts Manual page 24

1.10.1 Heating (Ignition) Failure
Heating (ignition) failure occurs when the ignition module fails to sense a flame within the 4-second time delay period
and locks out. When this happens, the module sends 24 VAC through the interface board alarm circuit to the
controller.
3000 controllers display "HEATING FAILURE."
The three primary reasons for ignition failure, listed in order of probability, are problems related to:
1. Gas and/or electrical power supplies
2. Electronic circuits
3. Gas valve.
PROBLEMS RELATED TO THE GAS AND/OR ELECTRICAL POWER SUPPLIES
The main indicators of this are that an entire battery of fryers fails to light and/or there are no indicator lights
illuminated on the fryer experiencing ignition failure. Verify that the quick disconnect fitting is properly connected,
the fryer is plugged in with connector twisted and locked, the main gas supply valve is open, and the circuit breaker
for the fryer electrical supply is not tripped.
PROBLEMS RELATED TO THE ELECTRONIC CIRCUITS
If gas and electrical power are being supplied to the fryer, the next most likely cause of ignition failure is a problem in
the 24 VAC circuit. Verify that the drain valve is fully closed. The valve is attached to a microswitch that must be
closed for power to reach the gas valve (often, although the valve handle appears to be in the closed position, the
microswitch is still open). If the valve is fully closed, refer to Section 1.11.1, TROUBLESHOOTING THE 24 VAC
CIRCUIT.
Some typical causes of heating failure in this category include a defective sensing wire in the ignitor assembly, a
defective module, a defective ignition wire, and a defective ignitor.
Occasionally, a heating failure occurs in which all components appear to be serviceable and the microamp reading is
within specification, but the unit nevertheless goes into ignition failure. The probable cause in this case is an
intermittent failure of an ignition module. When the unit is opened up for troubleshooting, the module cools down
enough to operate correctly; however, when the unit is again closed up and placed back into service the module heats
up and fails.
PROBLEMS RELATED TO THE GAS VALVE
If the problem is not in the 24 VAC circuit, it is most likely in the gas valve, itself. Before replacing the gas valve,
refer to Section 1.11.2
TROUBLESHOOTING THE GAS VALVE
1.10.2 Improper Burner Function
With problems in this category, the burner ignites but exhibits abnormal characteristics such as "popping," dark spots
on the burner ceramics, fluctuating flame intensity, and flames shooting out of the flue.
"Popping" indicates delayed ignition. In this condition, the main gas valve is opening but the burner is not
immediately lighting. When ignition does take place, the excess gas "explodes" into flame, rather than smoothly
igniting.
The primary causes of popping are:

Incorrect or fluctuating gas pressure

Defective or incorrectly adjusted
combustion air blower

Inadequate make-up air

Heat-damaged computer or ignition module
.

Cracked ignitor or broken ignition wire

Defective ignition module

Cracked burner tile (typically causes a very
loud pop).
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