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VII. TROUBLESHOOTING:
THIS SECTION IS ONLY TO BE PERFORMED BY TRAINED, QUALIFIED SERVICE
PERSONNEL, AND NOT BY THE FURNACE OWNER.
NOTICE: Before troubleshooting, familiarize yourself with the Initial Startup,
Checkout Procedure, and Troubleshooting Flowchart.
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.
1. Check for 115VAC line supply voltage to the furnace. If there is no supply voltage, check fuses and
service switch.
c
CAUTION: When testing electrical equipment, always follow standard electrical procedures.
2. Make sure thermostat is calling for burner operation.
3. Check oil supply and make sure all valves are open.
A. DIAGNOSTICS:
To assist in troubleshooting this appliance, it is equipped with an integrated safety and ignition control
with diagnostics. Refer to control manual provided with burner for operation and fault codes.
If it is necessary to troubleshoot the flame sensor independently of the burner primary, the following
procedure may be used.
B. CAD CELL CHECKOUT PROCEDURE:
1. Stop burner and shutoff electrical power to the appliance.
2. Open burner junction box (on top of the burner blower) and remove the plug-in portion of the cad cell
by pulling it forward from and clear of the receptacle. Connect an ohmmeter across cad cell pins. With the
cell exposed to direct room light, the measured resistance should be less than 2500 ohms (in fact, it may
be less than 200 ohms).
3. Check the resistance across the cad cell pins with the cell covered (protected from exposure to
ambient light). The resistance should be greater than 20,000 ohms.
4. If cell resistances are different from above, replace the plug-in portion of cell, (Honeywell Part No.
130367).
5. Carefully reinsert the plug-in portion of the cad cell into the receptacle. If the cad cell appears to be
functioning correctly, troubleshoot the fan control module and the safety and ignition control (primary
control) module, according to the Honeywell instructions covering the devices.
The troubleshooting chart beginning on the following page should help identify the type of malfunction or
deviation from normal operation. To use this diagram, just follow the instructions in the boxes. If the
answer is yes or the condition is true, go down to the next box. If the answer is no or the condition is
false, go to the box on the right. Continue checking and answering questions and conditions in each box
until a problem and/or repair is found. After any maintenance or repair, the trouble shooting sequence
should be repeated until normal system operation is achieved.
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