Lennox OF23Q3/4-105 - Troubleshooting: Safety Lockout Issues; Burner Locks Out on Safety; Loses Flame and Locks Out

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.
a
t
e
l
y
j
umper
across flame
If fire is
g
ood
,
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 con
t
ro
l
.
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
If burner con-
tinues to run
(d t l k
Too much air − − lean short fire
Reduce combustion air − check
combustion.
Poor Fire
(does not lock
out of safety),
fault may be
Too little air − − long dirty fire
Increase combustion air − check
combustion.
fault
may
be
due to poor
fire. Inspect
fi
Excessive draft
Adjust barometric damper for
correct draft.
After burner
p
fire.
Too little draft or restriction
Correct draft or remove restric-
tion.
After
burner
fires, immedi-
ately jumper
If fire is
g
ood
,
Dirty CAD cell face Clean CAD cell face.
Flame Detector
ately jumper
across flame
detector termi-
If
fire
is
good
,
fault is in the
flame detector.
Ch k d t
Faulty CAD cell − − exceeds
15000 hp
Replace CAD cell.
Fl
ame
D
e
t
ec
t
or
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.
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.
no
t
l
oc
k
ou
t
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.