12/08/2025- I arrived on site to find the unit functioning properly and without issue. The noise the customer was hearing was just the normal noise of the furnace startup process and the noise of the cold exhaust flue expanding due to the hot exhaust gas causing a small clicking sound during the initial startup. The furnace itself is working properly at this time and without issue, however the customer was also curious about having her ductwork cleaned, due to this I have sent her an estimate for any duct cleaning so the customer can sign and approve of the duct cleaning whenever she needs it done. I have verified that this unit is functioning and heating properly at the time of service.