Responded to a no-heat service call for a 20-year-old HVAC system showing control board fault code (6 flashes) and blowing cold air. Diagnostic inspection revealed both a faulty control board and a significant crack in the heat exchanger, which was documented with photos and shown to the homeowner via live camera. Although the crack has not yet extended past the crimp, the situation was explained as a safety hazard. Homeowner elected to contact local contractors before proceeding with repairs.
