Arrived on site to diagnose a 1987 Payne system located in laundry room closet. Client stated she shuts off system and unit does not turn off and fan keeps spinning. By passed thermostat and unwired thermostat wires off of board to see if system would shut off and still kept running. Jumped the heater directly and heater would turn on but fan would still turn on. Over all determined control board is bad and would need to be replaced to continue system Evaluation to ensure no other issues. Advised I would evaluate system in current condition and for safety. Found blower wheel is hammered of dirt. Filter was clogged and hammered. Motor is cover of oil and dirt from dirt entering system in past years. Found primary starter component was burnt up as well and some wires were burnt up from over heating from electrical. And heat exchanger was examined and found dimples to have a huge separation between them and it’s indefinite wear shows sign of high wear in past year and heat exchanger can