Facing a broken air conditioner on the hottest day is a quintessential American struggle. This complete guide demystifies common AC problems, from refrigerant leaks to frozen coils, and provides practical DIY troubleshooting tips that won't void your warranty. Learn when to call a professional and how to find a reliable HVAC contractor you can trust. Understand the critical cost factors and regional considerations that impact repair versus replacement decisions. Empower yourself with knowledge to maintain your cooling system efficiently and avoid costly emergency breakdowns.