Parts of tank in furnace room

[AJ_77]

In the interests of safety:

"Natural gas is colourless, non-toxic and odourless, although an odourant is added as the gas is fed into the distribution system. Known as mercaptan, this odourant is an important safety measure because it provides a distinct smell (much like the smell of rotten eggs) in the event of a gas leak. However, natural gas is lighter than air and rapidly dissipates into the air when it is released."

You would have to have a significant leak for enough to gather into concentrations high enough for ignition by the pilot. But it doesn't take much to smell it.

AJ