I have a gas heating stove that uses a wall thermostat. The stove will not light with the thermostat, but I can push the manual button and it will light. The wires are fine and I put in a new thermostat but it still does not work. I took the thermostat cover off and crossed the two wires, it still will not light. Why will it light when I push the manual button (that the thermostat is wired to) but not from the thermostat? New batteries, new thermostat - no luck.