Super honest about the small job=earns the big job
I called on a Sunday, aiming to make an appt for someone to come out during the week and Jonathan said he was going to be in my neighborhood so would happily stop over. SUNDAY!
We have a 20 year old high-effeciency furnace that has been acting a little funky, we were also smelling some gas coming from the exhaust. Jonathan came out and walked me through exactly what readings we should expect from the furnace. While he was doing his reading, he patiently explained what we were seeing, what it meant and how it affected the furnace. I was expecting him to try and sell me on a new furnace (which wouldn't have been out of line, given its age) but he said we had at least a year left and was just really honest about the shelf-life (he also quickly fixed what was causing the gas smell). It was the professionalism and honesty that was shown during a small maintenance check that is the reason I'm going to use him come spring to replace the unit (and the ductwork). I find that its really easy to dupe someone when they don't know what they are doing, but the best ones educate and are consultative, and thats what you're getting with Jonathan @ Cool Masters.