Arrived to HVAC maintenance. Upon arrival I made my way to the indoor unit and began my maintenance here. I began by performing a safety check of the heat exchanger which I found no noticeable concerns at this time. I then checked for proper blower operation. The blower motor was drawing correct amperage and the capacitor was performing within spec. There was substantial debris build up on the blower wheel however and the customer and I spoke about a duct cleaning along with a blower wheel cleaning. I then had the thermostat call for heat and began my furnace checks. The flame sensor (cleaned), igniter, and inducer motor were all operating within spec. I performed a combustion analysis with this performing properly as well. I replaced the air filter with truck stock. Next I had the system call for cooling and made my way to the outdoor unit. Here the refrigerant temps/pressures indicated a system charged below spec with refrigerant. I spoke to the customer about repair options and it w