I have a Rheem RRNL-B036JK06x unit. I have had the installer over a couple of times adjusting fan speed. Stock for this unit is Low for Heat and Medium for Cooling. Mine was set to Medium for Heat and High for Cooling. I had him come out and change the Heat to Low which worked out fine. I'm now undecided about the fan speed for the cooling part. I'm thinking of going to medium. Can I do this myself or do I have to have the installer over again? It only took him about 5 minutes to adjust it so it can't be that hard. I wish I would have went on the roof with him and watched him do it. He's probably going to charge me a service fee if I have him out again to do this.