I was called to a residential customer who was experiencing issues with their air conditioner. Upon inspection, I found that the air conditioner was not blowing cool air. The issue was a refrigerant leak and we performed an annual AC maintenance on a 10 year old Lennox cooling system. Cleared the drain lines and checked the evaporator coils, which were in good condition. Added refrigerant and replaced the air filters. The AC service was completed, and the customer's air conditioner is now perfoming efficiently ready for warmer weather.