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NO PREVIOUS
CODE
- Stored
codes
are erased after 72 hours.
On RED LED
boards stored status
codes can also be
erased
whenever
power
(115V or 24V)
is interrupted.
Run system through
a
heating or cooling cycle to check system.
BLOWER
ON AFTER
POWER
UP -
(115V OR 24V) - Normal
operation.
Blower runs for 90 seconds,
if unit is
powered
up during a call for heat
(R-W
closed) or when (R-W opens) during the
blower on-delay
period.
LIMIT CIRCUIT
LOCKOUT-
Lockout
occurs if the limit, draft safeguard,
flame
rollout, or blocked vent switch*(if used) is
open longer than 3 minutes.
Control will
auto-reset
after 3 hours. See code 33.
IGNITION
LOCKOUT-
System
failed to
ignite gas and prove flame in 4 attempts.
Control
will auto-reset
after 3 hours.
See status code 34.
GAS HEATING
LOCKOUT-Turn
off
power
and wait 5 minutes
to retry.
Check for:
- Stuck closed gas valve relay on control.
-
Miswire or short to gas valve wire.
ABNORMAL
FLAME-PROVING
SIGNAL
Flame
is proved while gas valve is de-
energized.
Inducer
will run until fault is
cleared.
Check for:
-
Stuck open or leaky gas valve.
PRESSURE
SWITCH
DID NOT OPEN
I
Check for:
-
Obstructed
pressure
tube.
-
Pressure
switch stuck closed.
SECONDARY
VOLTAGE
FUSE IS OPEN
Check
for:
- Short circuit in secondary
voltage (24V)
wiring including
thermostat
leads.
Disconnect
thermostat
leads to isolate
short circuit.
--€,
31
33
PRESSURE
SWITCH
DID NOT CLOSE
OR REOPENED
- tf open longer than 5
minutes, inducer shuts off for 15 minutes
before retry,
tf opens
during blower
on-
delay period, blower
will come on for the
selected
blower
oft-delay.
Check for:
- Proper vent sizing.
-
Low inducer
voltage
(115V).
- Low inlet gas pressure
(if LGPS used).
- Inadequate
combustion
air supply,
- Disconnected
or obstructed
pressure
tubing.
- Defective
inducer
motor.
- Defective
pressure
switch.
- Excessive
wind.
- Restricted
vent.
LIMIT CIRCUIT
FAULT-
indicates
the
limit, draft safeguard,
flame rollout,
or
blocked
vent switch*
(if used) is open.
Blower will run for 4 minutes
or until open
switch remakes
whichever
is longer,
tf
open longer than 3 minutes,
code
changes
to lockout #13.
tf open less
than 3 min. status code #33 continues
to flash until blower shuts off. Flame
rollout switch and BVSS requires manual
reset.
Check for:
-
Dirty filter or restricted
duct system.
-
Loose
blower wheel.
-
Defective
switch or connections.
-
Defective
blower
motor or capacitor.
-
Inadequate
combustion
air supply
(flame rollout
switch open).
-
Restricted
vent.
-
Proper vent sizing.
-
Excessive
wind.
34
IGNITION
PROVING
FAILURE-
tf flame
is not sensed
during the trial for ignition
period, the control will repeat the ignition
sequence
3 more times before lockout
#14 occurs,
tf flame signal is lost during
the blower
on-delay
period,
blower will
come on for the selected
blower oft-delay.
Check the following
items first before
proceeding
to the next step.
- Gas valve turned
off.
-
Manual
shut-oft
valve.
- Green/Yellow
wire MUST be connected
to furnace
sheet metal.
-
Flame sensor must not be grounded.
To determine
whether
the problem
is in
the gas valve, igniter, or flame sensor the
system can be operated
in the component
test mode to check the igniter.
First
remove the R thermostat
connection
from
the control
and initiate the component
test sequence.
Does the igniter
glow
orange/white
by the end of the 15 second
warm-up
period?
* Blocked vent switch used in Chimney
Adapter
Kit
I
Unplug igniter harness from control and initiate
another
component
test sequence.
Check
for 115V between
pin 1 and NEUTRAL-L2
on
the control.
Was 115V present
for the 15
second
period?
45
CONTROL
CIRCUITRY
LOCKOUT
Auto-reset
after 1 hour lockout due to:
Flame circuit failure.
-
Gas valve relay stuck open.
Software
check error.
Reset power to clear lockout.
Replace
control
if code repeats.
._-_
Replace
furnace
control.
_
Check for continuity
in the harness
and igniter.
Replace
defective
component.
Reconnect
the R thermostat
lead and set
thermostat
to call for heat. Connect
voltmeter
across
gas valve connections.
Does gas valve
receive
24V?
YES
Does gas valve open and allow gas to flow?
YES
I Do the main burners
ignite?
YES
I Do the main burners stay on?
Repeat
call for heat and check flame sensor
current
during trial for ignition period,
ts the
DC microamps
below 0.5?
._..O_t
Check
connections.
If OK, replace
control.
NOel
Check that all gas valves
are turned
on.
Replace
valve.
Check
for:
-
Inadequate
flame carryover
or rough
ignition.
-
Low inlet gas pressure.
Proper firing rate.
Blocked
or incorrect
carry- over gap.
(.045" nominal)
Allow blower
to come on and repeat test to
check for intermittent
operation.
YES
Clean flame sensor
with fine steel wool and
I
I
recheck current.
Nominal current
is 4.0 to 6.0
I
microamps.
I Is current
near typical
value?
__YES
Will main burners
ignite and stay on?
J
YES
I Fixed"
I
Check connections
and retry,
tf current
is
near typical value (4.0-6.0
nominal)
and
burners
will not stay on, replace
control.
__.._
Replace
electrode.
!_._
Replace
furnace
control.
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