Performed routine maintenance check on Lennox system (approx. 5 yrs old). Cleaned condensate pan & treated w/tablets to prevent algae. Coils in good condition - minor cleaning done. Filter replaced (customer had spares on hand). Checked all electrical components & connections - all good. System operating at proper pressures. No refrigerant needed. Recommended surge protector installation to protect circuit board during storm season. Will follow up next week with quote. Unit running quietly & efficiently after service.