30
Warnings: 
1. 
2. 
3. 
TACK APPROPRIATE STEPS TO KEEP CONTAMINATIONS OUT OF THE LINES, WHILE 
THESE LINE ARE OPEN TO ATMOSPHERE.
USE A OFMINIMUM 5% SILVER FOR COPPER TO COPPER CONNECTIONS. 
USE A OF MINIMUM 35% SILVER FOR COPPER TO STEEL CONNECTIONS. 
operation. Replace any if necessary. 
J. 
WHEN BRAZING, PURGE DRY NITROGEN THROUGH THE LINES TO PREVENT THE 
FORMATION OF OXIDES.
G.  Inspect all other components such as check valve and electrical components for proper 
H.  After all connections are made, open the service valves and pressurize to 150 psi with dry nitrogen,
I.   After leak testing ,recover any test refrigerant. 
Keep with (A) subpoints. 
Use the largest connections and hoses possible to expedite the process. 
charging procedures. 
Evacuate through both high and low side connections to the system. 
Break each vacuum with dry nitrogen to 3.0 psi. 
K.  Charge with clean, new or reclaimed R-22 refrigerant. Charge in accordance with proper 
L.  Re-check the system 24 hours of run time to verify the unit is free of acid. 
Evacuate to a level of 1500 microns twice and 500 microns the last time. 
7.  Other Check Points 
A.  Verify the operating voltage is within the specified range. 
E.  Inspect all the other electrical components for proper operation. 
F. 
I. 
 
 
 
! WARNING – Disconnect all electrical power to the unit before servicing. Disconnect power to 
both the indoor and outdoor units. NOTE: There may be more than one electrical disconnect 
switch. Failure to shut off power can cause electrical shock resulting in personal injury or death. 
 
B.  Check that all wiring connections are tight. 
C.  Verify that all fuses or circuit breakers are of the proper type and operational. 
G.  Verify all ducts and air moving device are sized and operate properly. 
Verify all the system are in correct position. 
D.  Verify the air conditioning operates properly in cooling. 
Verify the thermostat and subbase are correct and operate properly.     
H.  Verify the refrigerant piping is sized correctly and not pinched. 
Leak test with liquid detergent. If a leak is found, repair it after removing the nitrogen, and recheck. 
 
Symptom Possible Cause  Remedy 
Power off or loose electrical 
connection 
Make sure main switch is ON. Check and 
tighten all connections. 
Incorrect thermostat setting  Set thermostat correctly 
check the valve coil or replace it 
 
 
No cooling/heating 
replace it 
Dirty filters  Clean & replace 
Indoor air blockage  Check supply registers and return grills for 
blockage. 
Clear away leaves and other debris 
Improperly sized unit  Recalculate load 
Improper airflow  Check – should be 400CFM/Ton 
Incorrect refrigerant charge  Charge correctly per instruction. 
Air, non-condensable or moisture in 
system 
Recover refrigerant, evacuate & recharge, 
add filter drier 
 
 
 
 
 
Insufficient Cooling 
Incorrect voltage  At  compressor terminals, voltage must be 
within 10% of rating plate volts when unit is 
Water on floor or in 
furnace  trap 
Defective 4-way valve 
Blocked outdoor coil 
Compressor without pump function 
Blocked condensate drain and “P”  Remove blockage and clean drain lines, verify 
operation of condensate pump.
running. 
  
  Central Air Conditioning   Model: Condensing Unit, HC13-D2 
10.2 Troubleshooting Guide