He came back a second time when we called and asked a question that we had forgot to ask. Our mistake, our bad, but he came out anyway and addressed our concern. (We wondered if he had tested the heating and a smell, he had indeed, but tested it again and confirmed that the smell was normal upon first use after winter.)
He also, the first trip out, fixed a gap in the venting that was causing air leakage, did an outstanding job. Very friendly, very thorough, very knowledgeable.