Heating System Repair: I encountered a situation where a customer's heat pump was not defrosting properly, causing a decline in heating efficiency. Upon investigation, it became evident that the defrost sensor was malfunctioning. Taking swift action, I replaced the sensor and fine-tuned the heat pump, restoring its efficient operation. The client now enjoys a comfortably heated home, and to ensure continued performance, I recommended periodic heat pump maintenance to prevent similar issues in the future.