I had a oil guy come out and do a yearly maintenance on my furnace. After he left, I noticed an oil leak, so I had them come back out. The tech guy comes out and says "What the problem?" I said "I had yearly maintenance done on my furnace, and now it's leaking". He said "You should have just left it the fuck alone." I wanted to ask if this was his professional opinion, but I had quickly descided he wasn't being very professional.