Lennox OF23Q5-140 - Page 23

Page 23
Troubleshooting: Burner runs continuously (too little heat).
Source Procedure Causes Correction
Too much combustion air Reduce combustion air.
Low CO
2
less
Air leaks into heat exchanger
around inspection door, etc.
Correct cause of air leak.
L
ow
CO
2
l
ess
than 10%.
Excessive draft
Adjust barometric draft con-
trol for correct draft.
Incorrect burner head adjust-
ment
Correct burner head setting.
Dirty or plugged heat exchanger
Clean heat exchanger.
Hi h k
Di
r
t
y or p
l
ugge
d
h
ea
t
exc
h
anger
Readjust burner.
Check burner
High smoke
readin
g
more
Insufficient draft Increase draft.
Combustion
Ch
ec
k
b
urner
combustion for
CO2, stack tem-
reading
more
than a trace. Incorrect burner head adjust-
ment
Correct burner setting.
CO2,
stack
tem
perature, and
smoke
Too little combustion air Increase combustion air.
smo
k
e
Too little blower air
Increase blower speed to
maintain proper temp. rise.
Hi
g
h stack tem-
Blower belt too loose (if
equipped)
Tighten blower belt.
High
stack
tem
perature is
more than
Dirty or plugged heat exchanger Clean heat exchanger.
more
th
an
550
_F Net.
Dirty blower wheel Clean blower wheel.
550 F
Net.
Dirty furnace air filters Clean or replace filter.
Restricted or closed registers or
dampers
Readjust registers or damp-
ers.
Oil Pressure
Inspect fire and check
Partially plugged or defective
nozzle
Replace nozzle.
Oil
P
ressure
Inspect
fire
and
check
oil pressure.
Oil pressure is too low: less
than 100 psi.
Increase oil pressure top
100psi.