York CIDH018B21S, Service Manual

Page: 63 / 186

SM-18001-rev.1
3-41
TROUBLESHOOTING
Abnormalities of Devices
Other
Abnormalities
Cause Check Item
Action
(Turn OFF Main Switch)
Event
Excessively
Low
Suction
Pressure
Insufficient
Heating
Operation
Measure superheat.
Correctly charge
refrigerant after gas
leakage check and
repair.
Gas Leakage
or Insufficient
Refrigerant
Charge
Check temp. difference
of each part.
Remove clogging.
Clogging
of Suction
Piping
Check temp. difference
between inlet and outlet
of strainer.
Replace strainer for
outdoor unit or indoor
unit.
Clogging of
Indoor Unit/
Outdoor Unit
Strainer
Check thermistor for
defrosting.
Replace thermistor
for defrosting.
Defrosting is
Insufficiently
Completed
Check for any
short-circuits
to outdoor unit.
Remove cause of
short circuit.
Excessively
Low
Air Temp. to
Outdoor Unit
Heat
Exchanger
Measure field-supplied
pipes.
Use specified pipes.
Excessively
Small
Diameter or
Long Piping
Is outdoor unit heat
exchanger clogged?
Remove clogging.
Are there any obstacles
at inlet or outlet of
outdoor unit?
Remove obstacles.
Is service space for
outdoor unit sufficient?
Secure sufficient
service space.
Check outdoor fan speed.
Replace fan motor.
Insufficient
Airflow to
Outdoor Unit
Heat
Exchanger
Check for clogging. Remove clogging.
Check for connecting
cord and connector.
Replace connector.
Is there operation
sound from coil?
Replace coil.
Is thermistor on
compressor normal?
Replace thermistor.
Is thermistor
installed correctly
on compressor?
Correctly install it.
Failure or
Malfunction
of Electronic
Expansion
Valve
Calculate heat load.
Use larger unit.
Indoor Heat Load is Larger
than Heating Capacity
Check for any
short-circuited
outdoor unit air.