3---3/3---4
3.6 NO EVAPORATOR AIR FLOW OR RESTRICTED AIR FLOW
No evaporator air flow
Motor burnout
4.18
Fan damage
4.18
Return air filter dirty
Check/4.19
Fan Relay EFR1 defective
Check/1.5/Replace
Safety device open
1.4
Wiring polarity incorrect
Check/5.1
3.7 EXPANSION VALVE MALFUNCTION
Low suction pressure with
Low refrigerant charge
4.9
high superheat
Wax, oil or dirt plugging valve orifice
Check/4.12
Ice formation at valve seat
4.7
Superheat setting too high
4.12
Power assembly failure
4.12
Loss of bulb charge
4.12
Broken capillary
4.12
Loose bulb
Check/Tighten
Low superheat and liquid
Superheat setting too low
4.12
slugging in compressor
Ice holding valve open
4.7/4.12
Foreign material in valve
4.7/4.12
Pin and seat of expansion valve eroded
or held open by foreign material
4.12
Broken capillary
4.12
Fluctuating suction pressure
Improper bulb location or loose bulb installation
4.12
Low superheat setting
4.12
3.8 NO HEATING OR INSUFFICIENT HEATING
Insufficient heating
Dirty or plugged heater coil
Check/Clean
Coolant valve malfunction or plugged
4.15
Low coolant level
Check
No heating
Coolant valve malfunction or plugged
4.15
Controller malfunction
15.a./3.5
Boost pump relay or pump malfunction
1.5.e/2.3.3
Safety device open
1.4