Nine years ago, Horizon Heating & Air Conditioning installed my A/C unit on a neighbor's…read morerecommendation. About two years later, the thermostat's WiFi feature failed. It was inconvenient, but the system otherwise worked fine, so we lived with it.
About two and a half months ago, the unit stopped working entirely. I called Horizon, and they sent a technician. He quickly diagnosed a clogged condensation line that was triggering a safety shutoff designed to prevent flooding in the crawl space where the unit is located. As a non-practicing mechanical engineer myself, his explanation seemed reasonable. He cleared the line with a brief burst from a small CO2 cartridge, got the system running again, and left.
A few days later, the system failed again. The same technician returned and this time proposed installing a new bypass condensation line along our garage wall, a considerably more invasive and expensive solution, arguing that the line had clogged again. On both visits, I specifically mentioned that the thermostat had also been cycling on and off by itself. Each time, however, he attributed that behavior to the condensation-line safety shutoff and did not inspect or test the thermostat. He left after the second visit with the system still down.
When the invoice for both visits arrived, I paid it without objection.
This is where Horizon actually lost me--not over a possibly incorrect diagnosis, but over what happened next.
A week later, I called the office with a specific request. The CO2 cartridge had discharged for only a fraction of a second before the technician recommended replacing the entire line. Before committing to something so extensive, I thought a proper, sustained high-pressure flush deserved a try. I explained my reasoning to the office manager and asked whether that could be attempted first. He seemed receptive and said he would check with the technician and get back to me.
I never heard back.
A week later, I called again and asked for the office manager but was told he was on another line. I explained my concern to the receptionist and asked that my message be passed along.
Again, nothing.
With temperatures still extremely high, I waited several more days and called once more. This time I reached the answering machine and left a detailed message recapping my previous calls, again asking whether a thorough flush could be tried before replacing the line and requesting a callback.
Still nothing.
Shortly afterward, my wife and I left on a trip. By the time we returned, the indoor temperature had become a serious problem, particularly for my wife, who had recently undergone surgery. More than two weeks had now passed since my last call, with still no word from Horizon.
At that point, I decided to write directly to the company president, whom I had met when he came to quote the original installation nine years earlier. I laid out the history calmly, deliberately avoided naming or criticizing any individual employee, and simply asked that someone call me to schedule another visit.
That letter went unanswered for nearly two weeks.
In all, I made four separate attempts to get Horizon to address the problem: two phone calls, a detailed voicemail, and a courteous letter to the company president. Not one received a response. My phone's call log further illustrates the pattern: between July 1 and August 24, I placed nine calls to Horizon and received a single one-minute call back from them. What might initially have been an honest oversight became a repeated failure to communicate, particularly frustrating during a period of extreme heat.
I eventually received a referral to another HVAC company. Their technician spent approximately two hours thoroughly flushing the condensation line using nitrogen, water, and vinegar, clearing debris that the brief CO2 treatment had apparently left behind. Even after the line was fully cleared, however, the unit still would not turn on.
On a subsequent visit, they inspected and replaced the thermostat --
the same component I had repeatedly flagged to Horizon but which their technician had never tested. The system has run perfectly ever since. The fact that thoroughly clearing the condensation line did not restore operation, while replacing the thermostat did, strongly suggests that the thermostat was a significant part of the problem all along.
Contractors can misdiagnose a problem. That happens, and by itself it would not have prompted me to write this review. What I find unacceptable is what came afterward. I remained courteous throughout, paid Horizon's invoice without objection, and asked only that a technician return and try a more thorough flush before I committed to replacing the condensation line. Yet there was no follow-up from the office manager, no response to my second call, no response to a detailed voicemail, and not even an acknowledgment of a courteous letter to the company president.
That is ultimately why Horizon lost me as a longtime customer.
