I have a carrier 38ckc060370 that runs but the air is not cold coming out of the vents. i checked the copper line coming out of outdoor unit and is not cold either. does this mean that i need a recharge, or could there be some other problem? recently, i've had problems getting the unit to turn off, and had to use the breaker because it would not shut down on its own, but other than that, the unit has never had a problem. the unit is about 4 years old.

Kindly check outdoor unit fan Motor running or not . and it may possible blockage in the copper tubes (/capillary)/.need to internal clean by nitrogen flushing.

Trydisconnecting unit from power for few minutes and connect it back, this should reset the unit.

Assuming the outdoor unit is running, make sure the fan motor on top is turning and the compressor is running. They both must operate for the unit to function.

The easiest and most common problems:
1. Condenser coil is stopped up with dirt. The condenser coil is the radiator looking coil that wraps around nearly the whole outdoor unit. It can be washed out with water and a sprayer, just make sure you don't bend the aluminum fins and disconnect power before washing it out.
2. Low on refrigerant. If you don't have guages you can't check the refrigerant on your own. If the fan and compressor are running , feel the bigger copper line coming from the outdoor unit going into the furnace. It should be cold. If not you can either be low on refrigerant or the compressor valves are weak.

Hope this helps. If the unit is not running outside, repost and I will try to diagnose differently.

Check the outdoor unit to see if it is discharging hot air out of the top ofd the unit, check the insulated suction line to make sure it is cold or sweating. Try to listen to the outdoor fan and the compressor to make sure they are both operating

If the humming is your compressor running (feel the large copper line going into the unit, it should feel cold aftter a few minutes of run time) then the fan motor or the capacitor or both need to be replaced, check for voltage to the fan motor when the unit is "humming" if it has voltage and will not start replace the fan motor and the capacitor. hope this helps.

hi how are you...you say your outdoor unit is not working...is thermostst set in heat or cool when this is happening....if the compressor is running,go outside put your hand on the big copper line,if it is hot,your in heat mode,if it is cold your in cool mode..is it heatpump or ac only...if ac only ,you have a sequencer stuck ,or contactor closed keeping heat on...please chek items first...michael doctor airr appl.repair 843-384-8474...if need help call,ill help talk you diagnosis of problem...

if the the outdoor unit is running and the larger of the two copper lines going into the unit from the house is not cold you are probably low on freon. if the line is iced up then you need to shut if off for 8 hrs and try again, make sure the filter is clean recheck the large copper tube again if its not cold your probably low on freon. if its not running at all outside check your breakers. there are a number of diffrent things that may be wrong and you probaly need a service company to look at it.

Mac

How long before it goes from cold to hot. The compressor could be not running and going out on overload. The condeser fan could have failed. Did you check the outdoor unit. Is it running? Is the fan running on the outdoor unit. It could be low on charge which would cause ice. Are you getting excessive condensation? Let me know and i can help you out more. Grab the large copper line outside that is insulated and tell me if it is cold. It should be cold like a Pepsi out of the fridge!

You will need to let the indoor fan run for several hours to defrost the indoor coil. it may take 12 hours to defrost you'll know when it's clear when the vents are blowing like usual again. Then run the unit for 5 minuits and check the large copper insulated line going to the outdoor unit. is it cold? if not you need a refrigerant charge. If it is then make sure never to run the unit below 70 degrees and check your air fliter and return duct for blockage of possible collapse. Also you may have a dirty indoor coil chac that and clean the outdoor one as well.

Make sure you let the blower run for a while after it freezes to make sure there is no more ice. Then run the unit. Check the refrigerant lines the large copper line that has insulation on it should be cold to the touch. If it runs for 10 minuits and is barely cold or warm you are low on refrigerant. If its starts out nice and clod then check your filter and retun ductwork for blockage you should not have noisy return air vents or that can indicate you have too small a return.

Also are the outdoor unit and indoor coil a match? Same tonage?
Is the furnace big enough to handle the tonage? (fan size)