LAARS U.H.E. - Service Manual - Manual (Page 25)

U.H.E Service Manual Page 25
Hot Surface Ignition Models:
Are safety circuits in normal position?
Does blower
energize?
Is there 120VAC
across the white and
black wires at the
blower?
(see photo at right)
Replace blower.
(see page 25)
Y
N
Refer to ignition module/
control board illustration.
Is there 120VAC between
P5(1) and P5(3)?
Repair/replace
wire harness.
Y Replace ignition module/
control board.
Y
N
N
Y
N
N
Is there 120VAC
across the white and
black wires at the
terminal 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 page 12)
Correct safety circuit problem per
safety circuit trace
(see page 27).
Y
Y
Is there 120VAC
across the white and
black wires at the
terminal block ?
(see photo at right)
N
N
Refer to ignition module/control board
illustration. Is there 120VAC between P5(1) and
P5(3)?
Y
Replace
ignition module/
control board.
Call technical
support.
Check amp draw through
BLACK wire lead of blower
motor. Is there .6 to 3.0
amps?
Replace blower.
(see “Blower Replacement
Procedure”)
N
Y Is Blower wheel secured to
blower motor shaft?
N
Y
Determine
power
source
problem
and
correct
25
Black wire leading to
blower motor looped
through amprobe.
120VAC check at
Terminal Block
Checking for 120VAC
(Black & White Wires)
IGNITION MODULE