On 25 Jan 2006 18:33:26 -0800, "Ether Jones"
wrote:


I guess I wasn't clear. I do not have an "owner's manual". I never
got one. I do not know who installed the furnace.

Even if I did have an owner's manual, I doubt the information I am
seeking would be in there.

For example: If the ignitor is burnt out (open circuit), does the
control detect this and refuse to open the gas valve? Or... does it
open the gas valve, and then detect no flame, and turn the valve back
off?

I only know about stoves, but stoves do it a third way. (There is
almost always, in every area of thought, more than two ways.)

Ini a stove with a hot surface ignitor, the control supplies power to
the ignitor/valve circuit, and when current through the ignitor is
sufficient, it allows the valve to open.

If the ignitore is burned out (rare, right?) no current flows through
the valve becuase it is in series with the ignitor.

Maybe furnaces are different.

Stuff like that.

EJ


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