Having issues getting my Natural Gas Heater to light. I use to have a troubleshooting sheet that walk you down a decision tree but have misplaced it. Anyone now where to get on on net? Mine is a LG or Natural Gas and if I jump across TH the main valve will light and it will run for a period of time but eventually shutoff. I have cleaned all the contacts twice and still no luck . Yesterday tried to jump some of the other possible issue but no luck on getting it to fire on the pressure switch or the fuse connection . It does fire off if I jump across the two white wires on the terminal strip . This terminal strip has like 4 pairs of terminals. On one side you have what I think is the Fireman Terminal and on the other side think the white leads that come from the high limit switches . It appears to run until the temperature on the dial is reached. So is this telling me I have a bad high limit switch ? Why a 150F high limit and a 135high limit ? Help