102
T-Series Climate Changer Air Handler IOM •
CLCH-SVX06A-EN
Diagnostics
Low refrigerant coil
capacity
Incorrect airflow
Check fan operating condition.
Expansion valve is not operating properly or is
sized incorrectly
Check sensing bulb temperature.
Verify valve operation.
Verify proper valve size.
Incorrect refrigerant charge
Verify refrigerant charge and adjust if necessary.
Condensing unit failure
Verify condensing unit operation.
Coil is piped incorrectly
Verify coil piping (see the “Coil Piping and
Connections” section on page 49.)
Clogged refrigerant line filter
Change filter core.
Failure of suction/liquid line components
Verify component operation
Dirty fin surface
Clean the fin surface (see the “Coils” section on
page 62).
Do not use steam to clean refrigerant coils.
Fin frosting
Verify defrost cycle operation.
Verify frostat operation.
Verify refrigerant charge.
Low steam coil capacity Incorrect airflow
Check fan operating condition.
Coil is piped incorrectly
Verify coil piping (see the “Coil Piping and
Connections” section on page 49).
Incorrect steam pressure
Verify steam pressure and adjust if necessary.
Excessive steam superheat
Check steam superheat.
Steam superheat should not exceed 50ºF.
Failure of steam line/condensate return
components
Verify component operation
Boiler failure
Verify boiler operation
Dirty fin surface
Clean the fin surface (see the “Coils” section on
page 62).
Drain pan is overflowing Plugged Drain Line
Clean drain line
Unit not level
Level unit
Improper trap design
Design trap per unit installation instructions
Standing water in drain
pan
Improper trap design
Design trap per unit installation instructions
Unit not level
Level unit
Plugged drain line
Clean drain line
Wet interior
Coil face velocity too high
Reduce fan speed
Improper trap design
Design trap per unit installation instructions
Drain pan leaks/overflows
Repair leaks
Condensation on surfaces
Insulate surfaces
Excess dirt in unit
Missing filters
Replace filters
Filter bypass
Reduce filter bypass by ensuring all blockoffs are in
place.
Microbial growth (mold)
inside air handler
Standing water in drain pan
See “Standing water in drain pan” above
Table 18. Air handler troubleshooting recommendations
Symptom
Probable Cause
Recommended Action