Frymaster 35, 45 manual Improper Temperature Control, Melt Cycle, Failure to Control at Setpoint

Occasionally, a burner may appear to be operating correctly, but it shows a slow recovery rate (discussed on Page 1-18). The primary causes of this are low burner manifold pressure and misaligned or missing deflector targets. In some cases, the cause is a gas valve regulator that is out of adjustment. Refer to Section 1.3.2 for instructions on checking the burner manifold pressure and Section 1.3.4 for adjusting deflector target positioning.

Improper Temperature Control

Temperature control—including that for the melt cycle—is a function of several interrelated components, each of which must operate correctly. The principal component is the thermostat (in units equipped with thermostat controls) or the temperature probe (in fryers equipped with other types of controllers). Depending upon the specific configuration of the fryer, it may also include an interface board and controller. Problems with improper temperature control can be categorized into those issues concerning melt cycle malfunctions and those concerning a failure to control at setpoint.

Melt Cycle

In fryers equipped with thermostat controls, the melt cycle is controlled with a solid state melt cycle board and a melt cycle switch on the control panel. In all cases, replace the defective component.

In fryers equipped with other types of controllers, the problem may originate in the controller, the temperature probe, or a malfunctioning heat relay on the interface board. For problem isolation techniques, refer to the troubleshooting guides, Troubleshooting the Thermostat and Troubleshooting the Temperature Probe, in Section 1.7, Troubleshooting.

Failure to Control at Setpoint

In fryers equipped with thermostat controls, the problem will be in the thermostat. Refer to Section 1.3.5 for instructions on calibrating the thermostat. Possible causes are that

•the thermostat is out of calibration,

•the knob or flexible shaft is loose on the thermostat shaft,

•a thermostat wire is disconnected or broken, or

•the thermostat is defective.

Refer to Section 1.3.5 for instructions on calibrating the thermostat. In fryers equipped with other types of controls, the problem may originate in the temperature probe or probe circuit, the interface board, or the controller. Refer to Troubleshooting the Temperature Probe, Section 1.7.4., for problem isolation techniques.

Gas Valve Malfunction

Occasionally, a gas valve may malfunction. Use Section 1.7.2, Troubleshooting the Gas Valve, to determine if the valve has failed.

Computer Malfunction

Before diagnosing problems related to a computer controller, it is important to understand the use and significance of sensitivity and recovery.

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