Lennox OHR23-105 - Page 22

Page 22
Troubleshooting: Burner starts and fires, but lock out on safety.
Source Procedure Check Causes Correction
Poor Fire If burner
contin es to
Unbalanced fire Replace nozzle
continues to
run, this may
be due to
Too much air − −lean short
fire
Reduce combustion air − check
combustion.
be
due
to
poor fire.
Inspect fire.
Too little air − − long dirty
fire
Increase combustion air − check
combustion.
After burner
p
Excessive draft Adjust barometric damper for correct
draft.
After
burner
fires,
iditl
Too little draft or restriction Correct draft or remove restriction.
Flame
Detector
,
immediately
jumper across
If fire is good,
fault is in the
Dirty cad cell face Clean cad cell face.
Detector
jumper
across
flame detector
terminals at the
primary control.
fault
is
in
the
flame
detector.
Check
Faulty cad cell − exceeds
15000 hms
Replace cad cell.
primary
control
.
Check
detector
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
control.
Primary control circuit
defective
Replace primary control.
Troubleshooting: Burner Starts and Fires, but Loses Flame and Lock Out on Safety
Source Procedure Check Causes Correction
Poor Fire If burner continues
to r n (does not
Unbalanced fire Replace nozzle
to run (does not
lock out of safety),
fault may be due to
Too much air − − lean short fire Reduce combustion air −
check combustion.
fault
may
be
due
to
poor fire. Inspect
fire.
Too little air − − long dirty fire Increase combustion air −
check combustion.
Excessive draft Adjust barometric damper for
correct draft.
After burner
fires
Too little draft or restriction Correct draft or remove
restriction.
Flame
Detector
fi
res,
immediatel
y
If fire is good, fault
is in the flame
Dirty CAD cell face Clean CAD cell face.
Detector
immediately
jumper across
flame
detector
is in the flame
detector. Check
detector circuit.
Faulty CAD cell − − exceeds
15000 hms
Replace CAD cell.
detector
terminals at
the
p
rimar
y
detector
circuit
.
Loose or defective cad cell
wires
Secure connections or replace
cad cell holder and wire leads.
Oil Supply
the
primary
control.
If burner loses
flame (does not
Pump loses prime − air slug Prime pump at bleed port
flame (does not
lock out on safety),
fault is in the fuel
system.
Pump loses prime − air leak in
supply line
Check supply line for loose
connections and tighten
fittings.
system
.
Water slug in line Check oil tank for water (over
1 inch) pump or drain out
water.
Partially plugged nozzle or
nozzle strainer
Replace nozzle.
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