Found guest room z3 thermostat wiring for O had failed causing unit to run in heat when calling for cooling - replaced O wire with black wire for zone 3 at thermostat and zone control board. Z1 damper is 22x12 for a 24x14 duct - recommend replacement of zone damper to fit duct. Move dats to supply side. 14" angle 14x14 plate with 1/2" hem Add return to guest room: 8" start 8" 90 6x12x8 90 boot Sheet metal 8" flex 6x12 stamped return air grille