Heating Service Troubleshooting; Economi$Er Troubleshooting - Carrier 48TFD008-014 Installation And Service Instructions Manual

PROBLEM
Burners will not Misaligned spark electrodes.
ignite.
No gas at main burners.
Water in gas line.
No power to furnace.
No 24 v power supply to control circuit.
Miswired or loose connections.
Burned-out heat anticipator in thermostat.
Broken thermostat wires.
Inadequate heating. Dirty air filter.
Gas input to unit too low.
Unit undersized for application.
Restricted airflow.
Blower speed too low.
Limit switch cycles main burners.
Too much outdoor air.
Poor flame Incomplete combustion (lack of
characteristics. combustion air) results in:
Aldehyde odors, CO, sooting flame, or floating flame. Cracked heat exchanger.
Burners will not Unit is locked into Heating mode for a
turn off. one minute minimum.
PROBLEM
Damper Does Not Indoor (Evaporator) Fan is Off
Open
No Power to EconoMi$er Controller
No Power to G Terminal
Controller Fault
Thermostat Fault
Actuator Fault
EconoMi$er Minimum Position Set Incorrectly
Operation Limited to
Minimum Position
EconoMi$er Changeover Set Point Set Too
High or Too Low
Supply Air Temperature Sensor Faulty
Outdoor Air Temperature Sensor Faulty
Damper Position Supply Air Low Limit Strategy Controlling
Less than Minimum
Position Set Point
Damper Does Not CO
Return to Minimum
Position
Damper Does Not Damper Travel is Restricted
Close on Power Loss
LEGEND
IFM — Indoor Fan Motor
PL — Plug
Table 28 — Heating Service Troubleshooting
CAUSE
Table 29 — EconoMi$er Troubleshooting
POTENTIAL CAUSE
Ventilation Strategy Controlling
2
Check flame ignition and sensor electrode positioning.
Adjust as needed.
Check gas line for air purge as necessary. After purging
gas line of air, allow gas to dissipate for at least 5 minutes
before attempting to relight unit.
Check gas valve.
Drain water and install drip leg to trap water.
Check power supply, fuses, wiring, and circuit breaker.
Check transformer. Transformers with internal overcurrent
protection require a cool down period before resetting.
Check all wiring and wirenut connections.
Replace thermostat.
Run continuity check. Replace wires, if necessary.
Clean or replace filter as necessary.
Check gas pressure at manifold. Clock gas meter for input. If too
low, increase manifold pressure, or replace with correct orifices.
Replace with proper unit or add additional unit.
Clean filter, replace filter, or remove any restrictions.
Use high speed tap, increase fan speed, or install optional
blower, as suitable for individual units.
Check rotation of blower, thermostat heat anticipator settings,
and temperature rise of unit. Adjust as needed.
Adjust minimum position.
Check economizer operation.
Check all screws around flue outlets and burner compartment.
Tighten as necessary.
Overfired unit — reduce input, change orifices, or adjust
gas line or manifold pressure.
Check vent for restriction. Clean as necessary.
Check orifice to burner alignment.
Wait until mandatory one minute time period has
elapsed or power to unit.
Check to ensure that 24 vac is present at Terminal C1 (Common Power)
on the IFC (Indoor [Evaporator] Fan Contactor) or that 24 vac is present at
the IFO (Indoor [Evaporator] Fan On) terminal. Check whether 24 vac is
present at PL6-1 (red wire) and/or PL6-3 (black wire). If 24 vac is not
present, check wiring (see unit label diagram).
Check proper thermostat connection to G on the connection board.
Check to ensure that 24 vac is present across Terminals 24 VAC and
24 V COM on the EconoMi$er control. If 24 vac is not present, check wiring
(see unit label diagram). If 24 vac is present, STATUS light should be on
constantly.
If IFM is on, check to ensure 24 vac is present on G Terminal of the
EconoMi$er controller. If 24 vac is not present, check wiring (see unit
label diagram).
If STATUS light is flashing one flash, the EconoMi$er controller is
experiencing a fault condition. Cycle power to the controller. If condition
continues, replace the EconoMi$er controller.
If STATUS light is flashing two flashes, the EconoMi$er controller senses
the thermostat is wired incorrectly. Check wiring between the thermostat
and the connection board in the electrical panel. The fault condition is
caused by Y2 being energized before Y1.
Check the wiring between the EconoMi$er controller and the actuator.
Hold CONFIG button between 3 and 10 seconds to verify the
actuator's operation. (This process takes 3 minutes to complete.)
Verify that the MIN POS (%) is set greater than zero. Adjust MIN POS (%)
to 100% to verify operation, and then set to correct setting.
Set at correct value. See Table 4.
If STATUS light is flashing 4 flashes, Supply Air Temperature Sensor is
faulty. Check wiring or replace sensor.
If STATUS light is flashing 5 flashes, Outdoor Air Temperature Sensor is
faulty. Check wiring or replace sensor.
The supply-air temperature is less than 7 C (45 F), causing the minimum
position to be decreased. Refer to the Start-Up instructions. Verify correct
setting of MIN POS (%). If correct, EconoMi$er is operating correctly.
If a CO sensor is being used, and the damper position is greater than
2
minimum position, the ventilation control strategy is controlling. Refer to
the Start-Up instructions. EconoMi$er is operating correctly.
Check to ensure the damper is not blocked.
44
REMEDY
REMEDY