Carrier 48PG03-16 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 89

PROBLEM
Burners Will Not Ignite. Burners Will Not Ignite.
Inadequate Heating. Inadequate Heating.
Poor Flame
Characteristics. Characteristics.
Burners Will Not Turn Off. Burners Will Not Turn Off.
LED
FLASH DESCRIPTION
CODE
On Normal Operation
Off Hardware Failure
1 Flash Indoor Fan On/Off Delay
Modified
2 Flashes Limit Switch Fault
3 Flashes Flame Sense Fault
4 Flashes Four Consecutive Limit Switch
Fault
5 Flashes Ignition Fault
6 Flashes Induced Draft Motor Fault
7 Flashes Rollout Switch Lockout
8 Flashes Internal Control Lockout
9 Flashes Temporary Software Lockout
LEGEND
IGC --- --- Integrated Gas Unit Control
LED --- --- Light---Emitting Diode
NOTES:
1. There is a 3 ---second pause between alarm code displays.
2. If more than one alarm code exists, all applicable alarm codes will be
displayed in numerical sequence.
3. Alarm codes on the IGC will be lost if power to the unit is interrupted.
Table 96—Gas Heating Service Analysis
CAUSE
Active alarm.
No power to unit.
No power to IGC (Integrated Gas Control).
Heaters off due to time guard to prevent short cycl-
ing.
Thermostat or occupancy schedule set point not
calling for Cooling.
No gas at main burners.
Water in gas line.
Dirty air filters.
Gas input too low.
Thermostat or occupancy schedule set point only
calling for W1.
Unit undersized for load.
Restricted airflow.
Too much outdoor air.
Limit switch cycles main burners.
Incomplete combustion (lack of combustion air) re-
sults in: Aldehyde odors, CO, sooting flame, or float sults in: Aldehyde odors, CO, sooting flame, or float-
ing flame. i fl
Unit is in Minimum on-time.
Unit running in Service Test mode.
Main gas valve stuck.
Table 97—IGC Board LED Alarm Codes
ACTION TAKEN BY
CONTROL
—
No gas heating.
5 seconds subtracted from
On delay.
5 seconds added to Off
delay (3 min max).
Gas valve and igniter Off.
Indoor fan and inducer On.
Indoor fan and inducer On.
No gas heating.
No gas heating.
If heat off: no gas heating.
If heat on: gas valve Off
and inducer On.
Gas valve and igniter Off.
Indoor fan and inducer On.
No gas heating.
No gas heating.
Check active alarms using ComfortLink™ Scrolling Marquee.
Check power supply, fuses, wiring, and circuit breakers.
Check fuses and plugs.
Check using ComfortLink Scrolling Marquee.
Check using ComfortLink Scrolling Marquee.
Check gas line for air and purge as necessary. After purging gas
line of air, allow gas to dissipate for at least 5 minutes before at-
tempting to re-light unit.
Drain water and install drip.
Replace air filters.
Check gas pressure at manifold. Refer to gas valve adjustment on
page 110.
Allow time for W2 to energize.
Decrease load or increase of size of unit.
Remove restriction.
Check economizer position and configuration. Adjust minimum
position using ComfortLink Scrolling Marquee.
Check rotation of blower, thermostat heat anticipator settings,
and temperature rise of unit. Adjust as needed.
Check all screws around flue outlets and burner compartment.
Tighten as necessary.
Cracked heat exchanger, replace.
Unit is over-fired, reduce input. Adjust gas line or manifold
pressure.
Check vent for restriction. Clean as necessary.
Check orifice to burner alignment.
Check using ComfortLink Scrolling Marquee.
Check using ComfortLink Scrolling Marquee.
Turn off gas supply and unit power. Replace gas valve.
RESET METHOD
—
Loss of power to the IGC. Check 5 amp fuse on
—
IGC, power to unit, 24V circuit breaker, transformer,
and wiring to the IGC.
Power reset. High temperature limit switch opens during heat
exchanger warm-up period before fan-on delay
expires.
High temperature limit switch opens within
10 minutes of heat call (W) Off.
See Limit Switch Fault.
Limit switch closed, or High temperature limit switch is open. Check the
heat call (W) Off. operation of the indoor (evaporator) fan motor.
Ensure that the supply-air temperature rise is within
the range on the unit nameplate. Check wiring and
limit switch operation.
Flame sense normal. The IGC sensed a flame when the gas valve should
Power reset for LED reset. be closed. Check wiring, flame sensor, and gas
valve operation.
Heat call (W) Off. 4 consecutive limit switch faults within a single call
Power reset for LED reset. for heat. See Limit Switch Fault.
Heat call (W) Off. Unit unsuccessfully attempted ignition for 15 minutes.
Power reset for LED reset. Check igniter and flame sensor electrode spacing,
gaps, etc. Check flame sense and igniter wiring.
Check gas valve operation and gas supply.
Inducer sense normal, or Inducer sense On when heat call Off, or inducer
heat call (W) Off. sense Off when heat call On. Check wiring, voltage,
and operation of IGC motor. Check speed sensor
wiring to IGC.
Power reset. Rollout switch has opened. Check gas valve opera-
tion. Check induced-draft blower wheel is properly
secured to motor shaft.
Power reset. IGC has sensed internal hardware or software error.
If fault is not cleared by resetting 24 v power, re-
place the IGC.
1 hour auto reset, or Electrical interference is disrupting the IGC
power reset. software.
89
REMEDY
PROBABLE CAUSE
—