19
LEGEND
TXV —
Thermostatic Expansion Valve
PROBLEM CAUSE REMEDY
System noises.
Piping vibration. Support piping as required, check for loose pipe
connectors.
Expansion valve hissing. Add refrigerant, check for plugged liquid line
strainer.
Compressor noisy. Check valve plates for valve noise, replace
compressor (worn bearings), check for loose
compressor holddown bolts.
Insufficient compressor oil. Add oil.
Compressor loses oil.
Leak in system. Repair leak.
Plugged or stuck compressor oil return
check valve.
Repair or replace.
Oil trapping in line. Check piping for oil traps.
Crankcase heaters not energized during
shutdown.
Replace heaters.
Frosted suction line.
Expansion valve admitting excess
refrigerant.
Adjust expansion valve.
Hot liquid line.
Shortage of refrigerant. Repair leak and recharge.
Frosted liquid line.
Receiver shutoff valve partially closed or
restricted.
Open valve or remove restriction.
Restricted catchall. Replace.
Restricted strainer drier. Replace.
Frosted expansion valve.
Ice plugging TXV orifice. Apply hot wet cloth to TXV.
Moisture indicated by increase in suction
pressure.
Install drier.
Plugged TXV strainer. Clean strainer or replace TXV.
