Initial complaint: No heat in the house. On arrival, inspected furnace and found ignition failure error code causing lockout. Furnace installed in 2020—performed full inspection, including: Gas pressure test (low and high fire). Temperature rise test (on the threshold but not below it, possibly undersized furnace). Combustion analysis test. Issue was caused by a dirty flame sensor—cleaned the flame sensor and checked operation. Flame sensor is now working normally. Furnace is operating safely and normally at this time, within manufacturer specifications and current gas codes. If issue persists, recommend replacing the flame sensor on return visit if needed. - Wes