I was told by a plumber who was told by another electrician that you can not use bx or mc when wiring a boiler, gas or oil. I have been wiring boilers for years using bx or mc. He said your supposed to use greenfield with thhn. but i thought thhn is already in the bx/mc, so why do twice the work. He said he thinks it has to do with temp. rating on the conductors.Is there any codes or information out there for wiring boilers gas or oil?
The only think that I could find do far is from the mechanical code:
"304.2 Conflicts.
Where conflicts between this code and the conditions of listing or the manufacturer?s installation instructions occur, the provisions of this code shall apply.
Exception: Where a code provision is less restrictive than the conditions of the listing of the equipment or appliance or the manufacturer?s installation instructions, the conditions of the listing and the manufacturer?s installation instructions shall apply."
From:
http://www.peerlessboilers.com/Prod...9/tabid/204/Default.aspx#dnn_relateddocuments
"This appliance is to be wired in accordance with local
codes and regulations as defined by the Authority having
jurisdiction. In the absence of such local codes, the
PUREFIRE boiler is to be wired in accordance with the latest
edition of the National Electrical Code, ANSI/NFPA 70."