Filter
Top Products
Source Procedure
Thermostat Disconnectthermostat
wires at the primary
control.
• Burner turns off: ther-
mostat circuit faulty.
Primary • Burner not turning off:
control primary control faulty.
Combus-
tion
Oil Pres-
sure
Check burner
combustion for CO2,
stack temperature, and
smoke
• Low CO2 less than
10%.
• High smoke reading
more than a trace.
• High stack tempera-
ture is more than
550F net.
Inspect fire and check
oil pressure.
Too much heat
Causes
Shorted or welded thermostat contacts
Stuck thermostat bimetal
Thermostat not level
Shorted thermostat wires
Thermostat out of calibration
Thermostat in cold draft
Defective primary control
Too little heat
Too much combustion air
Air leaks into heat exchanger around
inspection door, etc.
Excessive draft
Incorrect burner head adjustment
Dirty or plugged heat exchanger
Correction
Repair or replace the thermostat.
Clear obstruction or replace thermostat.
Level thermostat.
Repair short or replace wires.
Replace thermostat.
Correct draft or relocate the thermostat.
Replace the defective primary control.
Insufficient draft
Incorrect burner head adjustment
Too little combustion air
Too little blower air
Dirty or plugged heat exchanger
Dirty blower wheel
Dirty furnace air filters
Restricted or closed registers/dampers
Partially plugged or defective nozzle
Oil pressure too low: less than 100 psi.
Reduce combustion air.
Correct cause of air leak.
Adjust barometric draft control for correct draft.
Correct burner head setting.
Clean heat exchanger.
Readjust burner.
Increase draft.
Correct burner setting.
Increase combustion air.
Check for high static pressure.
Check HEAT selector pin per wiring diagram
(figure 18, page 16).
Clean heat exchanger.
Clean blower wheel.
Clean or replace filter.
Readjust registers or dampers.
Replace nozzle.
Increase oil pressure top 100psi.
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O23V SERIES