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This code pretty much means that the contol board or electronics is not sensing or detecting the flame. It could be the control board or possibly the electrode or high tension wire. IF you can hear it trying to ignite (clicking) I would go cycle your main LP tank valve, close it very slowly and then open it slowly. Sometimes that can be the issue and the regulator can be locked up, you could have some LP flow but you want to rule that out, most likely if the other LP appliances are working then the furnance should which leads us to the control board and elctrode. I would find the control board check the contacts on the plug, look for any loose or corroded wires. IF you still have the same issue I would have that control board tested. most shops will charge a small fee and others will do it for no charge, these boards do fail. Next would be the electrode and many times it requires the furnance to be pulled so that it can be inspected, something like that I would let a shop handle, many times special gaskets are needed when everthing is put back together. A shop will charge about a hour to diagnose and another hour if the furnance has to be removed.
Hope this helps.. Robert
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