Why did my ac start blowing hot when it doesn't require a 134a charge?

If the AC comes on and blows, but doesn't blow cold, the most likely culprits are either a no or low refrigerant charge, or a failed compressor. If you've verified that your system does have a full charge - it's likely that your compressor is unable to develop normal operating pressures, even with a full charge of refrigerant, and it will need to be replaced. The accumulator can harbor contaminates that will damage your new compressor, so compressor manufacturers will not provide a warranty on your new compressor if the accumulator/reciever-dryer is not replaced at the same time. AC repairs can be expensive. Your best bet is to deal with a reputable shop, and fix it right the first time, rather than spending money trying to "save" money on cheaper fixes that don't get the job done. Good luck!

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