Nordyne O4HD-091A-14-FA-DV Installation, Operation And Maintenance Manual page 27

Table C-3: Oil Primary Control Troubleshooting continued.
Status Corrective Action
Indicator light is on. Remount control onto burner housing. Go to step 6.
Procedure
10. Check cad cell.
Disconnect line voltage power
and open line switch.
Remove existing cad cell and
replace with new cad celt.
Disconnect all wires from
thermostat terminals to ensure
that there is no call for heat.
Reconnect line voltage power
and close line switch.
Expose new cad celt to bright
light such as a flashlight.
11. Check cad cell bracket
assembly.
Disconnect line voltage power
and open line switch.
Remove cad cell wires from
quick connect connectors on
and leave control lead wires
open.
Apply power to device.
Place jumper across cad cell
terminals after burner motor
turns on.
Indicator light is off.
Indicator light is on.
Indicator light is off.
Go to step 11.
Replace cad cell bracket assembly.
Replace oil primary control.
NOTE: Restricted Mode - (Limited Reset): In order to limit the accumulation of unburned oil in the combustion chamber, the
control can be reset only 3 times, after which, the control locks out. The reset count returns to zero each time a call for heat is
successfully completed.
To reset from RESTRICTED MODE:press and hold the reset button for 30 seconds. When the LED flashes twice, the device has
reset.
NOTE: Disable function: Pressing and holding the reset button will disable all functions until the button is released. The burner
will restart at the beginning of the normal heat cycle on SAFETY CHECK.
Table C4: System and General Troubleshooting
Problem Possible Cause Remedy
Check thermostat and adjust. Also, check thermostat for
Thermostat not calling for heat.
accuracy; if it is a mercury switch type, it might be off level.
Check furnace switch, main electrical panel furnace fuse or
circuit breaker. Also took for any other hand operated switch,
No power to furnace.
such as an old poorly located furnace switch, which was not
removed during furnace replacement.
Furnace will not start. Remove thermostat wires from oil primary control terminals T-T.
Thermostat faulty. Place a jumper across T-T. If furnace starts, replace thermostat,
thermostat sub-base (if equipped), or both.
Check reset button on oil primary control. Remove thermostat
Oil primary control faulty, wires from oil primary control terminals T1 - T2. Check for 24V
across T -T. If no voltage is present, check for 115V to oil
primary control. If 115V is present, go to Table C-3.
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