Thomas left out the igniter, but only if it's a gas stove.

When he said it's the exhaust fan, I assume he means the little fan that clears the vent of combustible gases before the ignition kicks on the burners.

One moment it ignites a fire within us, filling us with enthusiasm and drive to accomplish our most ambitious goals.

What do you do if someone or faulty wire ignites the entire home.

The blower motor, an ignition module/sensor, cracked heat exchanger. 

They might leak but that would certainly be visible and unless it's a boat load of water it wouldn't reduce the heat output.The smoke on the exterior of the unit is from poor ignition which might be due to starving for combustion air (no fresh air supply in a small utility room) or the improper adjustment I mentioned before.

I replace ignition systems (module, plugs, and wires) every 100k miles.

My hope was to ignite a discussion on this and share data regarding the validity of that claim.Any suggestion that brings into question the ethics or integrity of my company I find to be offensive.

I always find it exciting to see that spark being ignited (or re-ignited)!

(an igniter once in a while, so what).