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Ok what you have is a dirty flame sensor. There are two things that have wires going to them. One is the spark ignighter and the other is the flame sensor. Use a small wire brush and clean off the one that isnt the iogniter. That should get you back up and running. If that doesnt work please let me know. FYI the cover plates on these can be a pain to get off. Just tweak it a bit and it will come off.
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OK. I think the thermocouple is bad. The pilot will light and the burner will light, but the fire goes out in about 45 to 60 sec. The pilot is not burning after this event. Also, How do you open up this area for the replacement. Do I have to disconnect the fuel supply to the burner? It appears as thought the plate removes as assembly. Is this so?
The flame sensor does the same job as the thermocouple. Your unit does not have a thermocouple like the oolder pilot light type units. If the flaame sensor does not see that the flame is present it will shut off the fuel until it does.
Try cleaning it off with a wire brush first. If that doesnt work then you will have to replace it.
Where is the flame sensor, How do I gain access to it?
There are two wires that go to where the pilot light usually sits. One is the igniter (has a small wire tip coming out of the end of it) and the other wire goes to the flame sensor (what would be the thermocouple in a pilot light system). Clean off the one without the wire tip.