Lennox O23, Installation Instructions Manual

Page: 21 / 23

Page 21
Troubleshooting: Burner starts and fires, but lock out on safety.
Source Procedure Causes Correction
Unbalanced fire Replace nozzle
If burner con-
ti
t
Too much air − −lean short fire
Reduce combustion air − check
combustion.
Poor Fire
tinues to run,
this may be
due to poor
Too little air − − long dirty fire
Increase combustion air − check
combustion.
due to poor
fire. Inspect
fire.
Excessive draft
Adjust barometric damper for
correct draft.
After burner
fires, immedi-
ately jumper
Too little draft or restriction
Correct draft or remove restric-
tion.
ately jumper
across flame
d t
t t i
If fire is good,
Dirty cad cell face Clean cad cell face.
Flame Detector
detector termi-
nals at the pri-
mary control.
If fire is good,
fault is in the
flame detector.
Ch
k d t
Faulty cad cell − exceeds 15000
hms
Replace cad cell.
mary control.
Check detec-
tor circuit.
Loose or defective cad cell
wires Secure connections or replace
cad cell holder and wire leads.
Primary Control
If burner locks
out on safety,
fault is in the
primary con-
trol.
Primary control circuit defective Replace primary control.
Troubleshooting: Burner Starts and Fires, but Loses Flame and Lock Out on Safety
Source Procedure Causes Correction
Unbalanced fire Replace nozzle
Too much air − − lean short fire Reduce combustion air − check
combustion.
Too little air − − long dirty fire Increase combustion air − check
combustion.
Poor Fire If burner con-
tinues to run
(does not lock
Excessive draft
Adjust barometric damper for
correct draft.
(does not lock
out of safety),
fault may be
Too little draft or restriction
Correct draft or remove restric-
tion.
After burner
fires immedi
If fire is good,
Dirty CAD cell face Clean CAD cell face.
Flame Detector
fires, immedi-
ately jumper
across flame
If fire is good,
fault is in the
flame detector.
Ch
k d t
Faulty CAD cell − − exceeds
15000 hms
Replace CAD cell.
Flame Detector
across flame
detector termi-
nals at the pri-
mary control
Check detec-
tor circuit.
Loose or defective cad cell
wires Secure connections or replace
cad cell holder and wire leads.
mary control.
Pump loses prime − air slug Prime pump at bleed port
If burner loses
flame (does
not lock out on
Pump loses prime − air leak in
supply line Check supply line for loose con-
nections and tighten fittings.
not lock out on
safety), fault is
in the fuel sys-
Water slug in line Check oil tank for water (over 1
inch) pump or drain out water.
Oil Supply
in the fuel sys
tem.
Partially plugged nozzle or
nozzle strainer Replace nozzle.
Restriction in oil line Clear restriction.
Listen for pump whine
Plugged fuel pump strainer Clean strainer or replace pump.
Cold oil − outdoor tank Change to number 1 oil.