Accepted Answer

<p>Yes your coil is frozen solid and will not allow any air flow thru it. You will have to shut outdoor unit off and leave the inside blower motor on and wait about an hour to hour and half to thaw out. Then you must check the air filter if its dirty it needs to be changed since this may be the cause of this problem. I have a canned list of what else to look for</p><p> </p><p> </p><ul><li>Overcharge of refrigerant or oil. </li><li>Compressor is oversized. </li><li>Uneven or inadequate evaporator loading, probably caused by poor air distribution. </li><li>Excessive accumulation of oil in the evaporator. Check the defrost controls for proper operation and add more defrost cycles. A minimum of four should be used. </li><li>Expansion valve bulb and / or equalizer tube located improperly on the system. </li><li>External equalizer line plugged or capped. </li><li>Expansion valve defective or held open by a foreign material causing liquid flood back. </li><li>Moisture in the system causing the expansion valve to freeze in the open position. </li><li>Evaporator fan blades are on backwards. </li><li>Oversized condenser. </li><li>Excessive subcooling. </li><li>Poor distribution of refrigerant thru the evaporator nozzle and circuits. Usually the bottom rows of the evaporator will freeze up when this occurs. There should be no more than 5 degrees F difference in the superheat between any two circuits as they enter the header. </li><li>Expansion valve defective or has the incorrect power element charge. </li><li>Interrupted pump down which will leave refrigerant in the low side. This creates the possibility of flooding on start up. </li><li>Oversized expansion valve. </li><li>Liquid migration on the off cycle. Install pump down controls and a crankcase heater. </li><li>The expansion valve, solenoid valve or the compressor discharge valve leaks. This will leave refrigerant in the low side which creates the possibility of flooding on start up. </li><li>Excessive evaporator coil icing. </li><li>Superheat setting on expansion valve too low. </li></ul>

Expert:	Rick Mather
Pos. Feedback:	96.2 %
Accepts:
Answered:	7/14/2009

HVAC Technician

35 years experience, HVAC