My broad themes are Art Deco & Steampunk. Fonts I like (but you are not limited to) are Academy Engraved LET, Jenson Classico, & Koch-Antiqua Zier. Website gives general idea: http://www.newenglandsteamworks.com
I think Steampunk is a good fit. However, a lot of Steampunk is fantastical and that would not be appropriate. The design needs to convey professionalism, seriousness of purpose, and steeped in history and tradition. Retro. Art Deco might work too.
The design may be a full or a partial wrap. I can't really envision which would look better at this point.
My logo designer died before the logo project was finished, so I have always felt that they are missing just a little something, like a background, or outline, or whatever. So if you agree, you may tinker with them. But only on the edges.
The required text is: "Efficient, Quiet, & Comfortable Steam Heat" + "Service, Installation, & Restoration Of Steam Heating Systems". Plus the website address, and the phone number with an old fashioned telephone symbol preceding it. Should be in one of the recommended fonts, or equivalent.