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17.6 Service Analyzer Charts
COMPRESSOR OVERHEATING
SYMPTOMS
POSSIBLE CAUSE
CHECK/REMEDIES
High superheat
Low charge
Check system charge
Faulty metering device
Restricted cap tube, TEV (TXV)
Power element superheat
adjustment
Foreign matter stopping flow
High internal load
Hot air (attic) entering return
Heat source on; mis-wired or
faulty control
Restriction in liquid line
Drier plugged
Line kinked
Low head pressure
Low charge
Operating in low ambient
temperatures
Suction or liquid line subjected
Hot attic
to high heat source
Hot water line
Low voltage
Loose wire connections
Check wiring
Power company problem,
Have problem corrected before
transformer
diagnosis continues
Undersized wire feeding unit
Correct and complete diagnosis
High voltage
Power company problem
Have problem corrected
High head pressure
Overcharge
Check system charge
Dirty heat pump coil
Clean coil
Faulty or wrong size
Replace fan motor
heat pump fan motor
Faulty fan blade
Replace fan blade
or wrong rotation
Replace with correct rotation motor
Recirculation of air
Correct installation
Additional Heat Source
Check for dryer vent near unit
Check for recirculation from
other equipment
Non-condensibles
Recover refrigerant, Evacuate and
recharge system
Equipment not matched
Correct mis-match
Short cycling of compressor
Faulty pressure control
Replace pressure control
Loose wiring
Check unit wiring
Thermostat
Located in supply air stream
Differential setting too close
Customer misuse
TEV
Internal foreign matter
Power element failure
Valve too small
Distributor tube/tubes restricted
Capillary tube
Restricted with foreign matter
Kinked
I.D. reduced from previous
compressor failure
