Trane TAMXB0A24V21DB - Page 68

68
18-GJ89D1-1F-EN
HIGH SUPERHEAT
Superheat above 30F at OD unit
Start Here
Verify line set is
properly sized for
application
NO
Verify that OD
condenser coils
are clean
Add refrigerant
until subcooling
reaches ~10F
Recheck
superheat
Verify line set size
and charge is
correct
NO
Perform
“OPEN VALVE”
test from
Diagnostics Mobile App
YES
Does
superheat drop
below 30F?
Is indoor
temperature
>85F?
NO
Perform
“CLOSE VALVE”
from Diagnostics
Mobile App
YES
Does suction
pressure go
down?
EEV and coil are working.
Replace AHC
Check operation
YES
YES
Perform
temperature
sensor check
YES
NO
Replace EEV
Check operation
Ohm coil per Stepper
Motor Tables
NO
Is ohm reading
correct?
YES
Replace EEV
Stepper Motor
NO
The system is running at
maximum capacity and
thismay be causing the
highsuperheat. Wait until
theindoor temperature is
less that 80F and check
thesuperheat again.
Is liquid line
temperature at the
indoor unit within 8ºF of
outdoor liquid line
temperature?
Is subcooling at
the outdoor unit
between 8-12F?
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