Performed heating maintenance on a 2020 Lennox SL280. Homeowner turned system on inside, unit started normally. Heating temperature split is 47 degrees. Filter had insulation and debris on it, homeowner wants to source his own filters. I cleaned the filter best I can. Sensors and switches were cleaned and tested. Gas valve was tested. Blower wheel and motor are clean and in range. Combustion blower is within spec as well. System is not electrically protected. Homeowner was briefed on the condition and signed up for scheduled maintenance. System was running at end of appointment.