I dealt with Artur a couple of years ago when my heater went out and knew that I had found someone I could trust to be honest, fair, and competent. My air conditioner went out recently and I thought it had something to do with my Nest thermostat. I spent an hour on the phone with Nest going through various procedures all to no avail. I called Artur late in the afternoon and he offered to come over within a couple of hours and I told him the next day would be okay as we had another AC on the other side of the house.
Artur came by the next morning looked over the wiring, which was fine, and discovered the problem. The door on the unit had vibrated loose from the last time I changed the air filter. The rocker switch which is held down by the door was open which shuts the system down. I felt like a moron that it was something so simple. He put the door back on properly and the AC popped back on immediately. I tried to pay him for his time but he would not take any money because it was so simple. Either that, or he has a policy to not take money from morons.
Artur Arzumanyan is honest, trustworthy, knowledgeable, and fair. I have no qualms recommending him.