Originally Posted by ducnut
I'd go to your town inspector and double-check what is code, before closing it in, just in case. I've encountered work from licensed contractors that wasn't to code. Likewise, one hopes the inspector is squared away, as well.
The use of galvanized versus black pipe comes down to the potential flaking and deterioration of galvanized causing plugged gas orifices and, also, the different strengths in the respective fittings. Where I live, black iron is code for gas; galvanized is only code for water.
Because you're not continuously running your heat, the colder, metal items are going to condensate, when you kick on the heat. That's just the way it is.
When the inspector came to do the final mechanical / plumbing inspection on my house he walked in, peeked under the kitchen sink, then went down stairs and slapped a sticker on the water heater. I estimated his total time for the final inspection at about 150 seconds. I wouldn't even trust an inspector to pick up bad work from the contractor. IIRC I did read that some gas was ok for galvanized pipe but can't remember what the circumstance was. I was always told the rule of thumb was black pipe and some types of copper. I buried copper pipe from the tank to the regulator on the building about 12" deep. I hope it was ok to use the copper for this?