Update, and more info. I have the heater vented with double wall pipe, which leaks into the heater when it rains from the NW even after siliconing the seams and all. It has been raining hard. The control does not get soaking wet but I did see a couple drops of water on the control's chassis. I took the control off and removed the back cover. Let it air out, but there was no visible moisture inside. I did however get it to fire with the lighter along with the pilot both directed on the flame sensor and it did light. Shut off and tried a couple more times and it got better...... flame sensor maybe? 3 year parts warrantee just ran out last week...... go figure. Any thoughts?