AskCodeMan

Jerry, Can you cite the code which specifically addresses flex (fuel line) through the sidewall of a furnace cabinet?
Thank you
-Marc

Hi Marc,

Did you verify if CSST or if an appliance connector?

Sorry, just an appliance connector. I keep hearing differing opinions...want to get it right once and for all.

Marc,

The code simply says to install the gas connector in accordance with the manufacturer's installation instructions.

The most common gas connector is likely this one: http://www.dormont.com/dmc/res/GasConnectors.aspx

The installation instructions for that one are attached. I will contact a person with more expertise in this than I am for the answer, but my reading of the installation instructions does not give an exception to "DO NOT install the gas connector so that it is concealed within or runs through any wall, floor or other partition." any wall, floor or other partition." would be that they are referring to a structure's walls, floor, or other partition, not that of an appliance. Let's see what the expert says.

I ran into this before with a Fire Marshal. After speaking with the head engineer at Dormont and Ted Lemoff at the NFPA, I concluded it is ok to pass a flexible appliance connector through the sidewall of an appliance cabinet IF it is sleeved in a conduit to protect it and electrically insulate it. Both ends of the connector must be 'accessible' for inspection and service. However, passing flex connectors through floors, walls, etc. or concealing even one end is strictly forbidden.

All the other code requirements still apply such as shutoff within 6ft., sediment trap, ground union, etc. Some AHJs will concede the flex connector functions as a ground union while others still require it in sch 40 pipe. Since unions are the #1 source of leaks, I'd leave it out if I used a flex connector. Be sure to size the connector as each foot de-rates it and in any case you cannot exceed 3' for a heater. Also, never re-use flex connectors.

In the case with CSST, it can penetrate an appliance cabinet if it, too is sleeved in conduit and electrically insulated from the cabinet.
HTH,

Wow...pretty interresting. Thanks for taking the time gentlemen.