Specifications

13
Unsatisfactory Cooling/Heating
■ Compressor is noisy. ■ Overcharge of refrigerant. Recover part of charge.
■ Broken internal parts. Replace compressor.
■ Broken valves. Test compressor efficiency. Replace if needed.
■ Expansion valve bulb loose. Tighten bulb bracket.
■ Loose hold-down bolts. Tighten bolts.
■ Heating Only—System runs—blows
cold air in heating.
■ Internal compressor overload open. Test continuity of overload.
■ Compressor stuck. Use test cord.
■ Shortage of refrigerant. Test for leaks. Add refrigerant.
■ Open element or limit on electric heater (heating only). Test heater element and
controls.
■ Overcharge of refrigerant. Recover part of charge.
■ Noncondensibles. Recover charge. Evacuate and recharge.
■ Broken internal parts. Replace compressor.
■ Inefficient compressor. Test compressor efficiency.
■ Faulty reversing valve. Replace valve or solenoid.
■ Faulty defrost control. Test control.
■ Faulty defrost thermostat. Test defrost thermostat.
■ Heating Only—Unit will not
terminate defrost.
■ Faulty reversing valve. Replace valve or solenoid.
■ Faulty defrost control. Test control.
■ Faulty defrost thermostat. Test defrost thermostat.
■ Heating Only—Unit will not defrost. ■ Faulty reversing valve. Replace valve or solenoid.
■ Faulty defrost control. Test control.
■ Faulty defrost thermostat. Test defrost thermostat.
System Operating Pressures
■ Low suction pressure. ■ Faulty evaporator fan motor. Repair or replace.
■ Shortage of refrigerant. Test for leaks. Add refrigerant.
■ Restricted liquid line. Replace restricted part.
■ Dirty air filter. Inspect filter; clean or replace as needed.
■ Dirty indoor coil. Inspect coil and clean, if needed.
■ Not enough air across indoor coil. Check blower speed. Check duct static pressure and
filter.
■ Dirty outdoor coil (heating only). Inspect coil and clean, if needed.
■ Wrong type of expansion valve. Replace valve.
■ Expansion valve restricted. Remove restriction or replace valve.
■ Undersized expansion valve. Replace valve.
■ Inoperative expansion valve. Check valve operation. Replace if needed.
■ Faulty defrost control (heating only). Test control.
■ Faulty defrost thermostat (heating only). Test defrost thermostat.
■ Low head pressure. ■ Shortage of refrigerant. Test for leaks. Add refrigerant.
■ Restricted liquid line. Replace restricted part.
■ Too much air across indoor coil (heating only). Reduce blower speed.
■ Broken valves. Test compressor efficiency. Replace if needed.
■ Inefficient compressor. Test compressor efficiency.
■ Wrong type of expansion valve. Replace valve.
■ Expansion valve restricted. Remove restriction or replace valve.
■ Faulty reversing valve (heating only). Replace valve or solenoid.
■ Faulty defrost control (heating only). Test control.
■ Faulty defrost thermostat (heating only). Test defrost thermostat.
■ Flowrator not seating properly. Check flowrator and seat, or replace flowrator.
Problem
No Cooling/Heating Cause/Test Method and/or Solution