Nordyne O4HD-091A-14-FA-DV Installation, Operation And Maintenance Manual page 25

IAWARNINGI
ELECTRICAL SHOCK HAZARD.
TROUBLESHOOTING IS DONE WITH THE
SYSTEM POWERED. BE CAREFUL TO
OBSERVE ALL NECESSARY PRECAUTIONS
TO PREVENT ELECTRICAL SHOCK OR
EQUIPMENT DAMAGE.
PRELIMINARY CHECKS:
Make sure that limit switches are closed and those
contacts are clean.
Check for line voltage power on the oil primary
control black and white lead wires.
Refer to Table C-4 or C-5 for further troubleshooting
information.
Table C-3: Oil Primary Control TROUBLESHOOTING
Condition: Burner motor does not start when there is a call for heat.
Status Corrective Action
N/A N/A
N/A N/A
Procedure
1. Check that limit switches are
closed and contacts are clean.
2. Check for line voltage power at
the oil primary control. Voltage
should be 120 Vac between the
black and white lead wires on the
oil primary control.
3. Check indicator light with
burner off, no call for heat (no
flame).
4. Shield cad cell from external
light.
5 Jumper thermostat (T-T)
terminals on oil primary control
IMPORTANT
First remove one thermostat lead
wire.
Indicator light is on.
Indicator light is off.
Indicator light turns off.
Indicator light stays on.
Burner starts.
Burner does not start.
Cad celt is defective, sees external light, or connections
have shorted. Go to step 4.
Go to step 5.
Eliminate external light source or permanently shield cad
cell.
Replace cad celt with new cad cell and recheck.
If indicator light does not turn off, remove yellow lead
wires from oil primary control and recheck.
If indicator light is still on, replace the oil primary control.
If the indicator light turns off, replace cad cell bracket
assembly.
Trouble is in thermostat circuit. Check thermostat-wiring
connections.
If connections are clean and tight, check thermostat wires
for continuity.
Disconnect line voltage power and open line switch.
Check all wiring connections.
Tighten any loose connections and recheck.
If burner still doesn't start, replace the oil primary control
If burner still doesn't start, check the oil burner motor. It
may be seized or burned out.
Condition: Burner starts then locks out on safety with indicator light flashing at 1 Hz rate (1/2 second on, 1/2 second off)
Procedure Status Corrective Action
1. Check that the limit switches
are closed and contacts are clean.
2. Check for line voltage power at
the oil primary control. Voltage ......
should be 120 Vac (nominal)
3. Check indicator light with
burner off, no call for heat (no
flame).
Indicator light is on.
Indicator light is off.
Cad celt or controller is defective, sees external light, or
connections are shorted. Go to step 4.
Go to step 5.
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