Thermo Products 36)- 80, 30 Viii. Troubleshooting, Power must be disconnected before servicing

All installations and services must be performed by qualified service personnel.

VIII. TROUBLESHOOTING

: Power must be disconnected before servicing.

Refer to the appendices of this manual for an electrical schematic, a connection diagram, flowcharts to assist in troubleshooting, product specifications, and a replacement parts list follow for this appliance.

A.Heating System:

Qualified HVAC and cooling contractors must perform all service.

NOTICE: Before troubleshooting, familiarize yourself with the Initial Startup, Checkout Procedure, and Heating System Troubleshooting Flowchart.

To assist in troubleshooting the heating section of this appliance, it is equipped with an integrated safety and ignition control with diagnostics. These diagnostics include an indicator light that relays the operational status of the control and can help in diagnosing the condition of the flame sensor.

Diagnostic Features

The Honeywell brand model R7184B (or alternate R7184U) safety and ignition control module used on this unit continuously monitors the operation of the heating system. If an abnormal condition occurs, the LED light on the control will rapidly flash indicating the operational status of the unit. In event this control malfunctions, the entire control should be replaced. It is not field-repairable.

In the event of an operational failure of the burner system, the rate of flashes, if any, of the ignition control module LED should be noted, before turning off power to the unit. Otherwise, power to the heating section will be interrupted and the control LED will not furnish the diagnostic flashing. It may be necessary to restart the furnace and have the failure occur again. For the model R7184B, under normal operating conditions, the LED will be continuously lit while the burner is operating.

If either control has sensed a flame failure, which was uncorrected by initiating another trial-for-ignition, the control will cease ignition trials and shutdown the burner, or “lockout”. The LED will continuously flash at a high rate (approximately 1/2-second “on”; 1/2 second “off”, for the model R7184B.

: If the appliance fails to relight after resetting the primary control twice contact a qualified service company. DO NOT continue to reset primary control.

The operational condition of the flame sensor, or “cad cell”, can be checked by depressing the reset button on the control module, while the burner is operating. Count the number of flashes of the LED and compare them to the table below.

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