I have an old 12 year old Rheem Furnace. The furnace starts its cycle by the following:
1. thermostat calls for heat.
2. Ignitor starts to fire.
3. Pilot lights.
4. Main burner starts.
However, the burner kicks off right away and the entire sequence starts all over again. I have already replaced the electronic ignitor and cleaned the sensor. The rest of the unit is relativetly clean... CAN YOU HELP???? there is no furnace company close by and the nearest one is far and expensive......