Form RZ-NA-I-LDAP, P/N 207733 (Rev 2), Page 39
Trial for
Ignition
Call for Heat
Is there a
spark across gap at
ignitor?
Does gas
ignite?
Is there minimum
flame current at the flame
sensor?
Is there
minimum flame current
at the control
module?
Replace control
module.
Check connections to
flame sensor or
moisture in bulkhead
connector.
Is the flame sensor
corroded?
Clean
flame
sensor.
Is the sensor
located in flame
correctly?
Replace flame
sesnsor.
Repositon flame
sensor.
Is gas flowing?
Is the ignitor
position correct in the
gas flow?
Check gas pressure and
supply voltage. If either
are low, correct and
repeat startup.
Reposition spark
ignitor.
Is there
24VAC at the gas
valve?
Is there 24VAC from
gas valve output on control
module to chassis?
Check wiring and
connections to gas
valve.
Replace ignition
control module.
Replace gas valve.
Is there
spark voltage at
control?
Check high
voltage wire
continuity.
Is there
24V P1-2 to power
control?
Replace control
module.
Check wiring and/or
24VAC transformer
output.
YES
NO
YES NO
YES
NO
YES
NO
YES
NO
YES
NO
YES NO
YES
NO
NO
YES
YES
NO
YES
NO
YESNO
DSI Integrated
Control Module
(Circuit Board) Trial
Troubleshooting
Flowchart
PROBLEM PROB ABLE CAUS E REMEDY
1.
No
ower to unit.
1.
Turn on
ower; check su
l
fuses or main circuit breaker.
2.
No 24 volt
ower to inte
rated circuit board.
2.
Turn u
thermostat; check control transformer out
ut.
3.
Inte
rated circuit board fuse blown.
3.
Correct cause. Re
lace fuse
t
e ATC or ATO, 32VDC, 3A
.
4.
No
ower to venter motor.
4.
Ti
hten connections at circuit board and/or motor terminals.
5.
Inte
rated circuit board defective.
5.
Re
lace inter
rated circuit board.
6.
Defective venter motor.
6.
Re
lace venter motor. See Para
ra
h 32.
Burner will 1.
Manual valve not o
en.
1.
O
en manual valve.
not li
ht 2.
Air in the
as line.
2.
Bleed
as line
initial s tartu
onl
.
3.
Gas pressure too high or too low.
3.
Supply pressure should be 5" - 14" w.c. for natural gas or 11" - 14"
w.c. for
ro
ane
as.
4.
No S
ark:
4.
a
Loose wire connections. a
Be certain all wire connections are solid.
Transformer failure.
Be sure 24 volts is available.
c
Incorrect s
ark
a
.c
Maintain s
ark
a
at 1/8".
d
S
ark cable shorted to
round. d
Re
lace worn or
rounded s
ark cable.
e
S
ark electrode shorted to
round. e
Re
lace if ceramic s
ark electrode is cracked or
rounded.
f
Burner not
rounded. f
Make certain inte
rated circuit board is
rounded to i
nitor.
Circuit board not
rounded.
Make certain inte
rated circuit board is
rounded to furnace chassis.
h.) Unit not properly grounded. h.) Make certain unit is properly field grounded to earth ground and
ro
erl
hased
L1 to hot lead L2 to neutral
.
i
Inte
rated circuit board fuse blown. i
Correct cause. Re
lace fuse
t
e ATC or ATO, 32VDC, 3A
.
j.) Faulty intergrated circuit board. j) If 24 volt is available to the integrated circuit board and all other causes
have been eliminated, re
lace board.
5.
Lockout device interru
tin
control circuit b
above causes.
5.
Reset lockout b
interru
tin
control at the thermostat or main
ower.
6.
Combustion air
rovin
switch
6.
not closin
.a
Make sure unit is
ro
erl
vented.
Remove obstructions from vent.
c
Re
lace fault
tubin
to
ressure switch.
7.
Fault
combustion air
rovin
switch.
7.
Re
lace combustion air
rovin
switch.
8.
Main valve not o
eratin
.
8.
a) Defective valve. a) If 24 volt is measured at the valve connections and valve remains
closed, re
lace valve.
Loose wire connections
Check and ti
hten all wirin
connections.
9.
Integrated circuit board does not power main valve.
9.
a
Loose wire connections. a
Check and ti
hten all wirin
connections.
b) Flame sensor grounded.
) Be certain flame sensor lead is not grounded or insulation or ceramic is
not cracked. Replace as required.
c) Incorrect gas pressure. c) Supply pressure should be 5" - 14" w.c. for natural gas or 11" - 14"
w.c. for propane gas.
d
Cracked ceramic at sensor. d
Re
lace sensor.
Venter motor will
not start
General Troubleshooting
