Arrived on site to preform a 20 point maintenance on a 2018 carrier system. Turned system on into heat mode verified proper heating sequence for this system. Heating was operating normally. Checked burners and made sure combustion was properly venting out the flue vent, out the attic. Took a temperature rise of the incoming air and outgoing air, temperature difference was within desired range. Switched unit into cooling mode, took a static pressure test, static pressure was a little high, ducting could be improved to help with static pressure. Also wanted to recommend a 5 in filter rack to be installed on your system to replace the 1in filter in the ceiling. 5 in filter well help keep the dust and debris out of the system better and more efficiently, only needs to be changed once a year vs every month in the 1in. Blower wheel is looking dusty and would recommend a blower pull and cleaning as well. Filter was changed 20X30X1. Customer provided new filter. Checked all safety’s and limi