Completed heating tune up today. Temperature rise is in range on both stages of heating. No CO detected during my visit today. Replaced humidifier water panel and verified proper operation of humidifier. Inspected heat exchanger and noticed some thermal stress but no cracks or real areas that were concerning. Cleaned flame sensor. Waxed unit. System operating as expected at this time. Thank you for choosing LBA. Your technician today, Jake. View visual findings from this job here - https://visionshare.xoi.io/?id=XA-E865-436E2FA468D741C7891D1A01279056DA