Norcold 821 ignitor issue

I would get the F showing when there was soot flakes on the burner that fell from above somewhere. Bang on that upper part to get the loose stuff down and clear off the burner slots so flame is good until next time.

Keep the right screw drivers handy to get that drip tray off and then the bottom part out so you can clear the flakes away whenever you get that F.

The issue is the ignitor is not sparking multiple times like it use to. One spark and it's done, there should be several attempts to lite.

Gap of the electrode is to close to the burner(or dirty burner) or the Piezo Tower is bad. If Piezo tower bad you replace the control board. My test is to remove the Electrode wire from the Piezo and use a Insulated screwdriver to see if the spark jumps to the screwdriver from the spade terminal of the Piezo. Just hold the metal end about 1/2 inch from terminal and the spark to spark continuously. If it sparks just once, replace the control board. TURN OFF THE LP or disconnect the LP solenoid of the refer when doing this test. Doug