Trane Foundation GBC Series Installation, Operation And Maintenance Manual page 36

T T r r o o u u b b l l e e s s h h o o o o t t i i n n g g
Table 15. Troubleshooting chart (continued)
Symptom
Low vapor - cool compressor -
iced evaporator coil
High vapor pressure
Fluctuating head and vapor
pressure
Gurgle or pulsing noise at
expansion device or liquid line
Circulating air blower and
inducer run continuously,
compressor will not start
Burners will not ignite
Inadequate heating
Poor flame characteristics
Both condenser fan and
compressor startup and
shutdown frequently (about
three minutes per cycle)
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Possible Cause
Low evaporator airflow
Operating below 65°F outdoors
Moisture in system
Excessive load
Defective compressor
TXV hunting
Air or non-condensible in system
Air or non-condensible in system
Manual reset overtemperature control tripped
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
Misaligned spark electrodes
No gas at main burners
Dirty air filter
Gas input to furnace too low
Unit undersized for application
Restricted airflow
Limit switch cycles main burners
Incomplete combustion results in: Aldehyde odors,
carbon monoxide, sooting flame, floating flame
Abnormal high discharge pressure caused the high
pressure switch act
Remedy
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 and recharge
Recover refrigerant - evacuate and 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'.
RT-SVX069A-EN