Preformed winter tune up on all 4 units. All units are preforming within manufacturer specifications and found no major issues. I spoke to homeowner about getting on maintenance agreement but he had to leave so I left estimates for that and a couple other items that I think we should address. Both of the xv systems have no surge protection, I suggested them because specifically these units have expensive parts especially the drive that is back ordered months. We now put them on at install to protect our units because of this and suggest having them on unit to protect your investment. In addition one of the single stage units had high starting amps and no in rush device like the other unit. These can cut the amp draw in half and prolong the life of the unit. I changed all the filters except the casida as there was no new filter. I took a picture so homeowner can order the correct one. The other 3 had different filters in the closet that I was able to use. It’s up to the homeowner which