On Mar 21, 1:19*am, kansascats wrote:
As I recall.. *3 burners fire at first.. and then after an extended
runtime (how much I don't know), the other two come on. * The theory
is that it may only take 3 to get the house to the desired temp ---
and then the others come of a bit later.

There is some black box -- about 1.5" square that has a dial on it
that says something about delay time.

It's a Maytag -- natural gas.

That may be possible if it's a two stage furnace. Not sure how
they all operate, but mine fires all burners whether at first stage
or second. For the lower firing rate the gas valve just reduces
the pressure. Seems like the best approach to me, as it uses
all the heat exchanger, which I would think would lead to a little
better efficiency. But there may be some furnaces that
do it by using less burners.

You may be able to find a manual for the actual furnace online
that describes how it operates. But, you are dealing with gas,
so unless you are experienced and know what you're doing,
I'd recommend getting a pro in.