FURNACE NOT OPERATING UPON ARRIVAL. Client would like a Furnace inspection due to cost and age of FURNACE. REMOVED HIGH LIMIT TO INSPECT HEAT EXCHANGER. Discovered heavy rust deposits and flaking on all 3 cells inside at first bend. NO signs of holes or cracks at the best of my ability. PERFORMED walk-through with client on Honeywell 800.Client does not have working Carbon monoxide device. INSTALLED 1 FROM TRUCK STOCK. Furnace is not operating at departure.