In my experience, Larry Kirchhoff demonstrated good workmanship and a high degree of professionalism. I am completely satisfied with the end result of this job, and I would not hesitate to contact him for future work. I had already purchased a humidifier, and I called Larry about installation. We scheduled an in-home estimate to determine cost of installation -- he was able to provide a lower-cost humidifier with similar characteristics, so we returned the unit we had purchased, and scheduled for Larry to perform the installation, and to service the furnace at the same time. Larry waived the estimate fee, and did not require a downpayment. He arrived promptly at the scheduled time, with one assistant, installed a flow-through style humidifier, and serviced the furnace. The cost of the job matched the price I was quoted, which included a small discount. I was satisfied with the work. The next day, I discovered water accumulating in the basement, where the furnace is located. I found that Larry's humidifier installation was not directly the cause. The output from the flow-through humidifier had been run to the same drain that receives the condensation from the A/C, and he explained this to me at the time of installation. Unfortunately, I found that the builders of the property improperly constructed the drain, which was thus unable to cope with the extra input from the humidifier; after a period of time, the drain had backed up. I called Larry to explain the problem, and he agreed to replace the flow-through humidifier with a drum humidifier, which produces no waste water during normal operation. He graciously performed this installation at no additional cost, and took time to carefully explain how to keep the drum humidifier clean. The drum humidifier is functioning well, and I've had no subsequent problems. I expect that many other contractors would have left me to fend for myself once the agreed-upon work had been completed and paid for. For Larry's professionalism and desire to ensure that a job is done correctly, I would recommend All Star Mechanical to anyone looking for a contracter specializing in Heating & A/C, without qualification.