For this job, I did a super tuneup. Changed the filter. Delta was 20. Inducer was in tolerance. No water safety so I recommended a drain float switch. When the compressor kicks on the lights in the home flicker, I suggested an easy start. Homeowner has about 4 inches of insulation, suggested he bring it up to an R value of 30. At the outdoor unit refrigerant was good, Capacitor was in tolerance, cleaned out the coil, and unit was cooling and running when I left.