27 yr old package unit failed combustion analysis with high carbon monoxide levels(1021ppm before I removed meter). This unit is condemned. Different 18 yr old package unit heat was not working. Found and replaced failed capacitor for draft motor. After we got this unit running we tested combustion analysis on it as well. This unit has also failed combustion analysis, was reading 7359 ppm of carbon monoxide levels and climbing. This unit is condemned as well. Appointment is scheduled Monday 3-5pm with comfort advisor for an estimate to replace units.