According to the instruction that is posted on my furnace, the pilot will ignite automatically when heat is required. However, I set the thermostat to the temperature (70F) that is higher than the room temperature (68F), then turn on the furnace, the pilot would not ignite. Then I lighted the pilot manually, the furnace started and worked, it stopped when the temperature reached to 7oF. It did not restart again when the temperature lower than 70F. In addition, I could not find the gas valve. Can anyone help me please.