1142* Jermane 910-316-5029 Jermane on site reported furnace 4 not heating. Stopped working and also making a loud noise. Tech found a nail in the inducer wheel. Tech removed the nail. Inducer is still running loudly. Bearings in inducer are making a grinding sound. After removing nail, pressure switch closed, but burners did not light due to a failed hot surface igniter. It is getting 120 volts but not heating up. Tech ohmed igniter and read OL across leads. Tech removed evaporator panel to inspect heat exchanger. There are several long rust lines on heat exchanger tubing, but it does not look like it has cracked all the way through. To repair furnace, we would need to order a new igniter and inducer assembly. Due to poor condition of heat exchanger, tech recommends replacing entire furnace. Furnace 4 is twinned to gas furnace 1. Gas furnace 1 is heating correctly. Tested cooling cycle for system 4. Dual run capacitor is in specs. Delta T is 15. Need to get repair vs replace o