I recently requested service from Rich's HVAC service out of Celina, Tn, my unit was sporadically…read moreheating, two guys arrived, they told that it had a bad expansion valve, at first, next they attached a set of gages, the gauges indicated that there was some freon in the unit (I saw the gauges), they immediately attached a cylinder of freon and begin charging/dumbing freon in the unit, they made no effort to find a freon leak with Refrigerant Leak Detector, which you always do before adding freon, they did not weight the cylinder before they started so they could weigh the cylinder when they were done to determine how much freon they actually used/charged the system, which it is the only way to know how much freon you actually put in the unit, they had absolutely no way to monitor the amount of freon they were adding to the unit, also it was cool day, effects readings, a trained technician would have used a "HVAV Refrigerant Recovery System/Equipment, that would have recovered the freon from the system, after evac they could put in a "Correct Weight Charge" based on the specification attached to the unit, as it turned out neither of these guys had attended any type of formal HVAC trade or Tech School or Factory School, leading to a diploma of certification, yes I did quiz them on this point, neither had any formal training, sad, previous owner passed away and these guys are the new owners, anytime you go into a sealed HVAC System and add freon, there are industry standards and practices you always follow, these are taught in appropriate HVAC program, there a way too many untrained Shade Tree folks out there who do not have the knowledge or expertise to be working on modern HVAC units, Always call an reputable HVAC company with a proven track record, who technician have attended and graduated from a certified HVAC program, several companies in Cookeville, Tn who fit the bill,
Do not be fooled by the old reviews posted on Yelp on this company, most are many years old, now there are new owners. My family had an HVAC Company, so I know a little what I talk about, Consumers and Customers be diligent on who you choose.