Upon arrival, I discovered the damper working as intended. After investigation, I determined that the damper for downstairs is calibrated to allow pressure to bleed downstairs when upstairs is heating/cooling. The system does not have a bypass to allow pressure relief when one zone is running. I advised the customer that our best bet to address this issue is to set up a dump duct over the stairs. There currently is a duct in the location and it is tied to the upstairs zone by a Y on another duct. We would need to disconnect that duct and seal the Y. The. We would need to run a “home run” duct from the supply side of the system to the preexisting supply boot. We will need to bring 8” , 9” , and 10” collars and ducts due to the duct size being unknown. The office is working on the cost for this service.
