Carrier 59SC2A - Page 81

18
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apis
Supooysefqnory,
Lepely
|
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31 LPS or HPS PRESSURE SWITCH DID
11 NO PREVIOUS CODE - Stored codes are NOT CLOSE OR REOPENED - If opens 45 CONTROL C/RCUITRY
erased after 72 hours. Run system during blower on-delay period, blower will LOCKOUT Auto-reset
be through a heating or cooling cycle to come on for the selected blower off-delay. after 1 hour lockout due
| check system. if LPS opens longer than 5 minutes, to:
inducer shuts off for 15 minutes before - Flame circuit failure.
retry. If HPS remains open for one minute - Gas valve relay stuck
after gas valve closes the furnace will shut open.
~ down and retry. If HPS fails to close on - Software check error.
42 BLOWER ON AFTER POWER UP — - three successive cycles the furnace will Reset power to clear
(115V OR 24¥V) — Normal operation. lockout for 3 hrs before retry. lockout. Replace
ee control if code repeats.
| Blower runs for 90 seconds, if unit is Check for:
e powered up during a call for heat (R-W - _. NO
closed) or when (R-W opens) during the ~ Proper vent sizing. Unplug igniter harness from control and —>| Replace furnace control.
blower on-delay period. - Air leak between vestibule and blower initiate another component test
rompenment if LGPS 4 »| sequence. Check for 115V between pin oe
~ Low inlet gas pressure (i used). *| 1 and NEUTRAL-L2 on the control. Was | YES| Check for continuity in the
43
LIMIT
CIRCUIT
LOCKOUT
—
Lockout
.
Reconnected
or
obstructed
pressure
115V
present
for
the
15
second
period?
»,|
harness
and
igniter.
Replace
— Lockou DING. “| defective component.
occurs if the limit or flame rollout is open - Defective or miswired pressure switches
> longer than 3 minutes. Control will auto- - Excessive wind
: : . Reconnect the R thermostat lead and set | NO =
resel after 3 hours. See code 33. : wees condensate ora saggin thermostat to call for heat. Connect y| Check connections. ff OK,
ine PIPING, P gging > voltmeter across gas valve connections. replace control.
. estricted vent Does gas valve receive 24V?
14 IGNITION LOCKOUT - System failed to - Defective Inducer motor. Check that all gas valves are
| ignite gas and prove flame in 4 attempts. - Low inducer voltage (115 VAC) YES turned on. Replace valve.
a Control will auto-reset after 3 hours. See
status code 34. 33 LIMIT CIRCUIT FAULT — Indicates the Does gas valve open and allow gas to
Lp imi i i flow?
Be limit, flame rollout is open. Blower will run NO
for 4 min. or until open switch remakes .
21 GAS HEATING LOCKOUT — Turn off whichever is longer. If open longer than 3 YES ie cou
: . ger. Hop g NO [| - Inadequate flame carryover
power and wait 5 minutes to retry. Check min, code changes to lockout #7. If open ioniti
:
:
8
.
P
Do
th
inb
ignite?
or
rough
ignition.
e for: less than 3 min. status code #4 continues O Me main bumers Ignte : i
: - Low inlet gas pressure.
- Stuck closed gas valve relay on control. to flash until blower shuts off. Flame P iri
Mew . ’ ” : YES - Proper firing rate.
Miswire or short to gas valve wire. rollout switch requires manual reset.
oNSSos8 blower wheel y YES
- Loose blower wheel.
22 ABNORMAL FLAME-PROVING SIGNAL ~ Defective switch or connections. Oo ihe mann on Allow blower to come on and
Flame
is
proved
while
gas
valve
is
de-
.
Dirty
filter
or
restricted
duct
system.
0
Ine
main
burners
stay
on:
repeat
lest
to
check
for
; ; : ; ~ Improper gas input adjustment. intermittent operation.
& energized. Inducer will run until fault is - Improper limit switch or no gasket unless NO
cleared. Check for: :
Stuck leak \ noted on switch. Check ti dret
~ stuck open or leaky gas valve. Repeat call for heat and check flame NO eck conneciions and retry.
sensor current during trial for ignition ~ Hf current is near typical value
34 IGNITION PROVING FAILURE - If flame ‘od. Is the DC mi below 0.5? P) (4.0-6.0 nominal) and bumers
23. PRESSURE SWITCH DID NOT OPEN - is not sensed during the trial for ignition b-— Period. 1s the LL MICTOAMPS NelOw Uv s will not stay on, replace
- Check for: period, the control will repeat the ignition NO control.
» - Obstructed pressure tube. sequence 3 more times before lockout #14 YES
- Pressure switch stuck closed. occurs. If flame signal is lost during the wv
on for tho selected blower otfdelay. Clean flame sensor with fine steel wool
24 SECONDARY VOLTAGE FUSE iS OPEN Check the following items first before and recheck current. Nominal current is
Check for: proceeding to the next step. 4.0 lo 6.0 microamps.
> ~ Short circuit in secondary voltage (24V) - Gas valve turned off.
wiring including thermostat leads. - Manual shut-off valve.
Disconnect thermostat leads to isolate » - Green/Yellow wire MUST be connected NO
short circuit. to furnace sheet metal. YES | ls current near typical value? —e| Replace electrode
- Flame sensor must not be grounded.
To determine whether the problem is in YES NO
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?
Will main burners ignite and stay on?
t YES
Fixed.
59SC2A