Product review (5 stars): Flame Sensor Works Perfectly.  Unfortunately, the Burners Were the Real Problem.
My 12 year old Goodman furnace GMS90703BXA sometimes had a problem starting. Sometimes it would start on the first attempt, sometimes on the second, sometimes on the third, and sometimes it would fail to start and go into the lockout state. The single LED flash on the control board said it the problem was the flame sensor. The behavior when it failed was that the flames would come on, but only be on for 2 or 3 seconds and then the flames would go out because the control board told the gas valve to shut. So, I replaced the flame sensor with this flame sensor. This did NOT fix the "fail to launch" problem. So, I ordered and installed the ICM286 control board. This ICM board is of much better quality that the original it replaced, but the new control board also did NOT fix the problem. Finally gave up and called an HVAC service guy. He tested the inlet gas pressure and it was fine. Then, with the covers off, he fired up the furnace. One look at the burners and he said that they were the problem. Apparently, the burner venturis rust after several years and this changes the diameter of the holes just enough to restrict the air/gas flow just enough so that the flame sensor sometimes didn't think the burner was on. After replacing all three burners, the furnace now starts the on the first attempt every time. Attached are pictures of one of the burners. The rust and corrosion can easily be seen. After watching the HVAC guy replace the burners, I now realize that I could have done that myself, if I had known that burners go bad. Hopefully, this will save someone the cost of calling out an HVAC guy when you can easily replace the rusted burners yourself. Since the new burners should last another 10 years and since the furnace is already 12 years old, I will not be replacing the burners next time. Next time I'll be replacing the whole furnace because it will have exhausted its service life.