During a prior visit, we performed a comprehensive diagnostic evaluation of the system due to ongoing operational issues. At that time, we verified incoming power to the outdoor unit, confirmed proper voltage through the disconnect, inspected wiring connections, and reviewed the system error codes. After completing the manufacturer’s recommended troubleshooting steps and consulting directly with Fujitsu technical support, Fujitsu determined that the outdoor control board had failed and advised replacement. During today’s visit, we replaced the outdoor control board as previously directed. After restoring power and starting the heat pump system, the system responded in the same manner as before: the indoor unit did not operate, and the outdoor condenser displayed an error code indicating an issue with the indoor unit. We then continued with further diagnostics, including verifying incoming line voltage, checking transformer output, and testing the thermistor at the evaporator coil. Ou
