What would you do - Tenant broke AC

[Soniel Estime]

Hello,

I have a tenant who stated that their AC was not working. This was strange because I had the AC assessed last year and refilled with Freon. It’s an older unit and I was planing on replacing in 2 to 3 years but the technician told me the reason the unit went out was because the tenants left the thermostat on at 45 degrees for several weeks, meaning the AC wasn’t able to turn off and reset. I got quoted $3500 to replace the unit and lines. The property wasn’t advertised with central air and it doesn’t state central air on the lease. Should I buy a few portable window units or replace the entire unit and line? Also how can I make sure that if it occurred again the tenant would assume that cost? What would you do?