Arrived on site to perform heating tune up on a 2014 Lennox package unit. System located on roof. Cycled system in heating mode to ensure system operating. Thermostat good. Found filters dirty and replaced filters. Recommend do so more often. Checked electrical compartment and components. Connections good and secured. Blower assembly and wheel accumulating light dust. Motor is good at this time. Amp drawls are in range. Inducer motor good. Found amp drawls at max on inducer as it’s pulling 1.0 and max rated at 1.0. Advised inducer motor is working hard and could fail in future if continues to pull max amps. Heat exchanger has heat impingement and hot spots developing from self wear in past years. Found safety flame sensor burnt up and oxidized. Cleaned sea roe but is still oxidized and burnt up from self wear in past years. Would recommend replacing due to it’s condition and it’s could stop working in future. Drain lines has some debris due to lack of filter change out as client