Lennox O23 User Manual

Page 34
Troubleshooting O23 / OHR23 / OF23 −1 through −4 Units
Burner fails to start.
Source Procedure Causes Correction
Thermostat in OFF or COOL Switch to HEAT.
Thermostat Check thermostat settings.
Thermostat is set too low
Turn thermostat to higher tem
perature.
Burner motor overload tripped Push reset button pump motor.
Safety Overloads
Check burner motor, primary
safety control, & auxiliary limit
it h
Primary control tripped on safe
ty
Reset primary control.
y
yy
switch.
Auxiliary limit switch tripped on
safety
Reset auxiliary limit.
Check furnace disconnect
Open switch Close switch.
Power
Ch
ec
k
f
urnace
di
sconnec
t
switch & main disconnect.
Blown fuse or tripped circuit
breaker
Replace fuse or reset circuit
breaker.
Broken or loose thermostat
wires
Repair or replace wires.
Thermostat
Touch jumper wire across ther
mostat terminals on primary
Loose thermostat screw con
nection
Tighten connection.
Thermostat
mostat
terminals
on
primary
control. If burner starts, then
fault is in the thermostat circuit
Dirty thermostat contacts Clean contacts.
fault
is
in
the
thermostat
circuit
.
Thermostat not level Level thermostat.
Faulty thermostat Replace thermostat.
Disconnect the flame detector
i t th i t l If
Flame detector leads are
shorted
Separate leads.
CAD Cell
wires at the primary control. If
the burner starts, fault is in the
Flame detector exposed to light Seal off false source of light.
the
burner
starts
,
fault
is
in
the
detector circuit.
short circuit in the flame detec
tor
Replace detector.
Primary or auxiliary control
Check adjustment. Set the
maximum setting.
Place trouble light between the
black and white leads. No light
indicates that no power is going
P
r
i
mary or aux
ili
ary contro
l
switch is open
Jumper terminals; if burner
starts, switch is faulty, replace
control.
Primary Control
i
n
di
cates t
h
at no power
i
s go
i
ng
to the control.
Open circuit between discon
nect switch and limit control
Trace wiring and repair or re
place it.
Low line voltage or power fail
ure
Call the power company.
Place trouble light between the
orange and white leads. No light
indicates faulty control.
Defective internal control circuit Replace the control.
Place the trouble light between
the black and white leads to the
burner motor. No light indicates
that no power is getting to the
motor.
Blown fuse Replace the fuse.
Burner
Place trouble light between the
black and white leads to the
Binding burner blower wheel
Turn off power and rotate the
blower wheel by hand. If seized,
bl
ac
k
an
d
w
hit
e
l
ea
d
s
t
o
th
e
blower motor. Light indicates
p
ower to the motor and burner
Sized fuel pump
blower
wheel
by
hand.
If
seized,
free the wheel or replace the
fuel pump.
power
to
the
motor
and
burner
fault.
Defective burner motor Replace the motor.

Lennox O23 Specifications

General

Brand	Lennox
Model	O23
Category	Furnace
Language	English