I returned to our clients home to address a previously cleared drain line. Theresa showed me a video confirming the primary drain line for the air handler is connected to the washer machine drain line. I did clear the line again for her today and insulated the PTrap to avoid condensation. She mentioned that the downstairs was again acting strange and not cooling. The zone board did show it was open and not sending power to the motor. I proceeded into the attic and found that it was closed in the attic. I then went back to the board and I did the low voltage wire to the downstairs zone. We discussed how this problem was intermittent because it had worked properly for 2 weeks prior. I apologized for not diagnosing the problem sooner and will create an estimate to replace both motor and zone control board.