Trane Oxbox 14 Seer Series Installation Instructions Manual page 30

Table 11-1 Trouble shooting chart (Continued)
SYMPTOM
Dirty air filter
Unit undersized for load
Compressor operates Thermostat temperature set too low
continuously
Low refrigerant charge
Air in system
Outdoor coil dirty or restricted
Registers sweat Low evaporator airflow
Restriction in liquid line, expansion device or filter
drier
High head-low vapor
Flow check piston size too small
pressure
Incorrect capillary tubes
TXV does not open
Dirty condenser coil
High head-high or normal
Refrigerant overcharge
vapor pressure - Cooling
Condenser fan not running
mode
Air or non-condensible in system
Low head-high vapor Defective compressor valves
pressures
Incorrect capillary tubes
Low evaporator airflow
Low vapor - cool
compressor - iced
Operating below 65°F outdoors
evaporator coil
Moisture in system
Excessive load
High vapor pressure
Defective compressor
Fluctuating head & vapor TXV hunting
pressure
Air or non-condensible in system
Gurgle or pulsing noise
at expansion device or Air or non-condensible in system
liquid line
Circulating air blower &
Manual reset overtemperature control tripped
inducer run continuously,
compressor will not start
Wire loose in limit circuit
Water in gas line
No power to furnace
No 24 volts power supply to control circuit
Miswired or loose connections
Burners will not ignite
Misaligned spark electrodes
No gas at main burners
Dirty air filter
Gas input to furnace too low
Unit undersized for application
Inadequate heating
Restricted airflow
Limit switch cycles main burners
Poor flame Incomplete combustion results in: Aldehyde odors,
characteristics carbon monoxide, sooting flame, floating flame
Both condenser fan and
compressor startup and
Abnormal high discharge pressure caused the
shutdown frequently
high pressure switch act
(about three minutes per
cycle)
POSSIBLE CAUSE REMEDY
Replace filter
Decrease load or increase unit size
Reset thermostat
Locate leak, repair, and recharge
Recover refrigerant, evacuate system, and recharge
Clean coil or remove restriction
Increase speed of blower or reduce restriction - replace air filter
Remove or replace defective component
Change to correct size piston
Change coil assembly
Replace TXV
Clean coil
Correct system charge
Repair or replace
Recover refrigerant, evacuate & recharge
Replace compressor
Replace coil assembly
Increase speed of blower or reduce restriction - replace air filter
Add Low Ambient Kit
Recover refrigerant - evacuate & recharge - add filter drier
Recheck load calculation
Replace
Check TXV bulb clamp - check air distribution on coil - replace
TXV
Recover refrigerant - evacuate & recharge
Recover refrigerant - evacuate & recharge
Reset or replace
Check wiring
Drain. Install drip leg.
Check power supply fuses, wiring or circuit breaker.
Check transformer.
Check all wiring and wire nut connections
Check flame ignition and sense electrode positioning. Adjust as
necessary.
Check gas line for air. Purge as necessary. NOTE: After purging
gas line of air, wait at least 5 minutes for any gas to dissipate
before attempting to light unit.
Check gas valve.
Clean or replace filter as necessary
Check gas pressure at manifold with that on unit nameplate
Replace with proper unit or add additional unit
Clean or replace filter, remove any restriction
Check rotation of blower, temperature rise of unit. Adjust as
necessary
Tighten all screws around burner compartment
Cracked heat exchanger. Replace as necessary.
Unit over-fired. Reduce input (change orifices or adjust gas line
or manifold pressure).
Check burner alignment
Inspect heat exchanger for blockage. Clean as necessary.
Reference to the remedy of 'High head-high or normal
vapor pressure-cooling mode'.
installation & owner's manual
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