12/6/25 Came out on a return visit to replace the zone board per the prior work order. After installing the board and running additional diagnostics, the board tested good. The issue was traced to a faulty sensor connected to the zone board, which was sending bad signals and causing the original problem. I explained this to the homeowner: we’ll refund the zone board, and bill only for the sensor and labor. Homeowner agreed. The replacement sensor is being ordered, and we’ll return ASAP to install and verify proper operation.