“I have a new hi-efficiency furnace and AC unit that was installed last May (2025), and had not needed the Heat mode until last week (late-October), and found it was not working. With the outside air temperatures being relatively mild but trending downward into the upper-60s during the day, needing the furnace was not urgent, and Crystal sent a technician within 48 hrs after my call. He found a ground in the system that affected the furnace but not the AC that had run flawlessly through the recent cooling season. He left after 1.5 hours of unsuccessfully locating the ground, but he "fixed" the controls so the furnace was now working as I had to leave. Several days later another technician came as scheduled and resolved the grounding problem within an hour. Both were well-trained, friendly and relatively young. My house was built in 1977 with Crystal installing the original Carrier brand furnace and AC. I've continued to use Crystal for replacement Carrier equipment in 1998 and in 2025. I rate both the Carrier brand and Crystal's installation and service at the highest 5 star level.”