AC fully charged, but air coming out of vents isn't cool.

[jjsmith2045]

Upstairs A/C unit wasn't cooling and we discovered our suction line wasn't sweating. We have now had 2 technicians over and we still don't have cold air.

Technician #1- Said unit was low on *****. Since he didn't notice any leaks outside he went to look inside. He said the oil residue on the coils showed there's a leak in the coil and the only option is replace the entire system because he no longer can install a coil for an R-22 system.

Technician #2- Said we were low 1 lb. of *****. Tested the air coming out of vents before charging and it was 70 degrees. Air going into system was 80 degrees. Used a detector and found ***** leaking from a joint that had a nut that was loose. He tightened the nut and couldn't detect a leak anymore. He charged the system and said the Superheat was reading 10. He was dumbfounded that the air temperature coming out of the vents didn't change at all, and the suction line still isn't sweating.

Obviously, something is still not working. Any ideas on what the problem is?

[monkey spanners]

Kink in the lineset. How long has the system been installed? Has it ever worked well? Second choice would be blocked filter drier.

Tech #1 is either dishonest or an idiot. Expect he is paid on commission so only way he makes a wage is selling lots of stuff. Before you start getting to upset at him, realise its customers wanting cheap callout fees that promote this kind of business practice...

[jjsmith2045]

I have found very few HVAC installer's that don't reply with a new install for every problem. Unfortunately, I've moved away from the only HVAC installer that I've found that I could trust.

The home 6 years old, and we've lived in the home for 4 years. As far as I can tell it's run fine in the past. I don't go upstairs much, but nothing wrong has ever been noticeable to me in the past.

[andyc425]

tell them to give you the pressures this will almost always tell an engineer what he needs to know im guessing its a simple split system? if you lost all the refrigerant from the leak then the engineer should pressure test with nitrogen identify the leak or leaks, repair, pressure test again, vacuum the system and then charge based on manufactureres specs for the given unit. If indeed the only problem is a leak then the unit will work once charged, however some engineers will try to add partial charge but unless they are experienced they will get this wrong.. If the unit has a filter drier then you can check it to see if it is blocked put your hand on each side they should be the same temperature (warm) if the one side is cold its blocked. if the drier is good and the charge is good then another reason is if the coil is iceing over then you probably have a txv fault this is the device that meters the refrigerant into the inside coil ( evaporator ) you will be able to identify this by looking at the valve if there is ice forming on the body its stuck closed. if this is not the case then check the filters and inside coil for cleanliness or any obstruction of airflow over the coil i take it your not a tech so i tryed not be to technical hope this helps