Customer had another company come out and diagnose 2015 Lennox system with a leak in the evaporator coil. Performed leak search and leak detector did not pick up leak. Leak is most likely in coil as Lennox has had a huge issue with leaks in the evaporator coil in that year. Recommend changing evaporator coil. Refrigerant pressures are good for now. System is cooling at this time. Customer wanted me to check out his other system as well. Tested it and found everything within normal operating range. Customer wants to replace evaporator coil, will call Lennox to order part and schedule repair.