For this job I performed a evaluation. The damper from downstairs failed and was not opening completely even when receiving a 24 v call. I have the home owner the option between a complete repair replacing the damper vs a temporary fix bypassing the damper completely and keeping it open at all times working from the upstairs thermostat control. The homeowner opted to do the temporary repair right now and will consider a complete repair in the future. No further abnormalities were noted, the system was cooling within normal upon departure. I did explain to the homeowner with the zone system working properly they will experience temperature differences between upstairs and down stairs pri.arily working through the upstairs thermostat. Thank you for choosing comfort experts, have a great day! P