I have always trusted Comfort-Air Engineering to do my PM (periodic maintenance) and check-ups on my Carrier Heat Pump (cooling and heating system), since my system was installed. They have always provided prompt, courteous, value-based service and helped keep my cooling/heating operating at peak performance. I like Comfort-Air Engineering's pre-pay service packages; easy-to-schedule and value-based check-ups in fall + spring to ensure my system is ready for the hot Texas summers and cool winters in San Antonio. I highly recommend Comfort-Air Engineering for all your cooling / heating needs.