I have a gas Carrier furnace, Model 58GS100-GB.
It's getting a little cooler here in Chicago, so I decided to make sure my furnace is working properly. When I turned up the heat the first time, I heard a lot of clicking, perhaps 30-60 seconds worth, before the whole furnace started up. I was a little concerned that the furnace wasn't sparking well or that there was poor air flow, so I turned off the furnace and then watched it ignite as my wife turned it on.
Almost instantly (the first click?) a small light ignites (it isn't always on, so I assume this isn't a pilot? forgive my ignorance), but the clicking noise continues for 30-60 seconds before the main gas is opened and the full flames occur. Within a certain time period, the fan turns on, and we have hot air. All of the flames appear to be a clean bright blue.
My questions -
I believe that the clicking is a sparking ignition, and it continues even though this little pilot is lit up right away. Is this normal?
Is that little light called a pilot light, even though it isn't always on?
What mechanism detects this pilot is on, before it turns on the main gas flow?
Thanks in advance for your help,