Need to remove and replace HVAC unit

Alpha near Mt Anderson, Reno NV

Description

Remove and replace HVAC unit. I have a HVAC unit that I cannot fix. I have another HVAC unit that I am not using. I want to test and run the unit that I am not using, then remove the inop HVAC unit and replace with the other unit. First step is to test the unit last known good. Units are about 40 yards apart on the roof of a building in Stead. First 6 photos are of last known good unit, last 4 photos are of older unit we cannot get parts or schematics for.