I performed a single heating maintenance on a 2015 zoned gas system. I checked amps, cleanliness, electrical, filter, and safeties. I observed that the blower is beginning to have build up, the system does not have a primary drain safety switch or surge protection, and the outdoor unit is in need of a deep cleaning. I provided options to address these areas, and the customer declined at the time of service. Customer wants to wait unit after the new year to proceed. We owe an air quality check on the cooling visit due to the machine not finding service.