Timeline of events

• 2-3 weeks ago: inspection was completed. No issues with A/C unit given in inspection report
• Day before close: Buyer did a walk through and notified me that the A/C was not blowing cold. I called an A/C technician and he came out and notified me that the refrigerant was low and would need to be topped off in order for the unit to blow cold again. I notified the buyer of this and told them they would need to take care of it themselves as it is classified as regular maintenance.
• Day of closing: Closed on property. Property sold AS IS
• Two days after closing on property: Buyer reaches out and states that he had an A/C technician come out and they told him the unit needs a new compressor, refrigerant refilled, and a few other minor things. Total for the repair is $1,700 and he's asking me how I want to go about paying to fix it.

Am I legally obligated to pay for this repair? I had zero knowledge of any issues with the A/C unit other than that it needed refrigerant, which I notified them of. The contract states the property is sold AS IS, and the A/C unit had zero issues at the time of inspection, less than three weeks prior.