I have an Amada 90 gas furnace with a dual stage Aprilaire 6202/6203 control panel, and an Aprilaire thermostat. When I turn on the thermastat for heat, the furnace turns on, the fan starts, the thermocoupler glows, and the burners light. Within about 10 seconds, it all shuts down, and begins the cycle all over again. (fan, burners, off!). Could someone please point me in the direction to fix this?