Maintenance call on two 2007 Armstrong air furnaces. The upstairs unit is in pretty good shape but the blower motor bearings have some play in them and the hot surface igniter is looking rough. The downstairs furnace has a crack in the heat exchanger so the gas was shut off here today to prevent potential carbon monoxide leaking into the home. The downstairs system is also missing a supply and return plenum. Neither system has a sediment trap on the incoming gas supply. The upstairs system also has signs of water leaking into the emergency pan in the past. There was also presence of oil coming out of the secondary drain line and on the furnace indicating a potential refrigerant leak. The upstairs system is running and heating at this time.