I would like to know what was the reason why the fire in a gas boiler
can be extinguished by itself. I have a relatively old boiler that
runs by natural gas to heat water for my baseboard heating units. A
couple days ago, somehow the fire in the boiler extinguished by itself
-- no fire, not even the pilot. The control switch was at the "ON"
position. But I didn't smell any gas. I can re-ignite the boiler
without any problem, and the problem has not returned; this is good.
But I would like to know why the fire in the boiler would be
extinguished in the first place.

I have the following specific questions:

- Would this happen when the natural gas supply was momentarily
running out of gas? But the fire in my relatively new water heater was
still burning while the fire in the boiler was extinguished. If the
natural gas supply was momentarily stopped, I would assume that the
fire in both the boiler and the water heater would be extinguished,
right?

- Is the boiler smart enough to automatically switch off the gas
supply when it senses that the fire is extinguished? I am asking this
because the control switch was at the "ON" position but I didn't smell
any gas.

- Will this happen when someone (like my 2-year-old child) toggles
the power switch of the boiler Off and On?

Thanks in advance for any info.

Jay Chan