Furnace is not operating because there was never a drain line attached to drain the furnace condensate. Acidic waste water was sitting in the furnace and is leaking out of the collector box in the rear of the secondary heat exchanger, indicating the water tight seal has failed. Furnace is not graded properly, causing condensate to pool in the evaporator drain pan. What appears to be biological growth has already formed in the drain pan. Indoor fan assembly is starting to get dirty.