BX or Metal Clad cable use in furnaces

[Maxim Kiss]

Today I inspected a system, where what looks like a MC or BX conduit cable connecting the airhandler's main disconnect on the wall to the box on the right side of the furnace (see attached picture). The cable is pulled through the furnace, and installed close to the burners, but looks intact. I absolutely cannot remember if such installation is OK or not. What do you think?

[David A. Andersen]

Beats the heck out of bare Romex going through there (which a always see)!

Are you concerned with the furnace heat? You are probably not into Thermal Imaging, but look up "emissivity". It is about a materials ability to absorb heat energy. This shielded cable will reject about 80% of the furnaces heat whereas other cables will only reject about 5%.

Which seems better to you?

There is a flame roll-out safety device right here to protect from flame roll-out.

[Maxim Kiss]

Thanks David,
Now that I look at it again, it looks fine to me. The cable has been there for 9 years or so and looks great!

[Eddie P. Chatterton]

i do not know why would you question the bx in the picture? there are plenty of control wires in the same area that if there was a problem the control wires would probably be the first to go.
ed

[Maxim Kiss]

I think I had a senior moment yesterday.