Performed oil heating pm on water heater and boiler Brushed and vacuumed flue pipes and heat exchangers Replaced oil filter, nozzles, and strainers Checked all electrical connections and safeties Performed combustion and smoke tests Boiler-5.2%o2 40 ppm co 0 smoke Water heater- 6.1%o2 37 ppm co 0 smoke Customer stated they have air in the lines again and would like a quote for an air removal device. Will look into pricing for both an air scoop and spirovent. While installing that we also have to replace the pressure relief. Piping is 1 1/4” before the manifold.