Question QUESTION: AC quit blowing cold, slowly getting warmer over apx. 3 month period. Had friend come charge system, (Lic.by state)after apx 1 day started blowing hot again. Friend came back by looked at system, did not have equip. to test but said it was obvious that I had leak. Called local contractor, they came out said that Evap. unit was bad. they replaced evap. unit ( Split System) the next day back to hot, they returned and charged unit again. Next day hot, they returned and said that I had bad compressor. I believe they missed diagnosed the problem originally. Need a professional opinion on this. I still have the old evap. unit, is there a test to see if it was bad.
ANSWER: Did the contractor say there was a leak in the evap. coil? If they replaced the evap. coil and had to recharge it the next day it would seem that there is still a leak in the system. You can seal and pressurize the old evap. coil to see if the leak was there. If the system stops working from loss of freon after only 1 day you must have a fairly large leak even if it is on the high pressure side of the system. It should be fairly easy to find.
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QUESTION: He stated that Evap. unit was bad. What pressure does the evap. unit need to be tested at. I truly believe that since the identical time ( 1 Day ) from first freon refill to blowing warm air, then replacement of evap. unit, then 1 day till blowing warm air that all along it was the compressor unit that was bad. The compressor has been identified now as leaking. You can look down through fan guard and see shinny/ oily substance on the copper tubing.
Answer The evap. coil can be pressurized to 50-100 psi and then checked the next day to if it has lost a significant amount(some pressure will be lost by removing and reattaching gauges). Is the compressor itself leaking(rare) or just one of the copper pipes in the condensing unit? If the leak is in the copper tubing(not the part with the fins attached) it is probably repairable. You gave no indication of the age of the system which may effect your decision as to whether to repair or replace the unit.
