Service Manual

Hot Surface Ignition Models:
Are safety circuits in normal position?
Direct Spark Ignition Models:
Is collector high limit switch and
pressure switch in normally closed
position?
Does blower
energize?
(For Direct Spark
Ignition models,
e
nsure control display
s
hows “Heating”, raise
temperature setpoint if
necessary)
Is there 120VAC
across the white and
black wires at the
blower?
(see photo at right)
Replace blower.
(see “Blower
Replacement
Procedure”)
Y
N
Refer to ignition module/
control board illustration.
Hot Surface Ignition Models:
Is there 120VAC between
P5(1) and P5(3)?
Direct Spark Ignition Models:
Is there 120VAC between
P7(5) and P7(3)?
Repair/replace
wire harness.
Y
Replace ignition module/
control board.
Y
N
N
Y
N
N
Is there 120VAC
across the white and
b
lack wires at the
t
erminal block ?
Hot Surface Ignition
Models ONLY:
Refer to ignition
module, is there 24
VAC between P3(7)
and ground?
Y
N
Thermostat not
calling for heat.
(see “Thermostat
Circuit Testing”)
Correct safety circuit problem per
safety circuit trace
(section “Blocked Vent Pressure
Switch Testing”).
Y
Y
Is there 120VAC
a
cross the white and
b
lack wires at the
terminal block ?
(see photo at right)
N
N
Refer to ignition module/control board
illustration.
Hot Surface Ignition Models:
Is there 120VAC between P5(1) and P5(3)?
Direct Spark Ignition Models:
Is there 120VAC between P7(5) and P7(3)?
Y
R
eplace
i
gnition module/
control board.
C
all technical
support.
Check amp draw through
B
LACK wire lead of blower
motor. Is there .6 to 3.0
amps?
Replace blower.
(see “Blower Replacement
Procedure”)
N
Y
I
s Blower wheel secured to
blower motor shaft?
N
Y
Determine
p
ower
source
problem
and
correct
Service Procedure EF-V
Blower Testing and Replacement
52
Black wire leading to
blower motor looped
through amprobe.
120VAC check at
Terminal Block
Checking for 120VAC
(Black & White Wires)
IGNITION MODULE
HOT SURFACE IGNITION MODELS
12
3
8
6
5
4
3
1
12
1
4
1
3
3
2
1
1
5
3
P2P4P5 P7P3
CONTROL BOARD
P10P9J1
DIRECT SPARK IGNITION MODELS
52