Our furnace started blinking one time after not lighting. We have changed the ignitor, gas valve and flame sensor. Everything it says one blink is. It has started a few times, but has a mind of its own. Now it does the same thing of trying to start the 3 times then the dreaded one blink. We have cleaned everything and we are at a loss. Could it be the board? Thank you

Ok, we have traced more information on this Goodman. The gas valve opened a few times and it has worked. The one thing that is not happening now is the gas valve is not opening anymore. This is a new part. The gas valve is connected to 3 things. The transformer, which seems to be working. The auxillery limit switch and the control board. The control board blinks the one time, stating the problem. But those parts have been replaced. Should we just replace all three of the other parts it is connected to. Thanks for any help.

I needing to change from natural gas to LP gas it's a GDT 090-4A

How to change from natural gas to LP ?