Venting not up to code going out the roof needs more pipe added to it, 6†air jet b-vent. No gas leaks detected with my meter checked before and after the cleaning son all gas joint and gas valve. Gas leak may have been from the gas burner install wrong from another service call. Performed cleaning on boiler. Preformed combistion Anaylasis CO: 27 O2: 8.1 CO2: 7.3 excess air: 63.2. Boiler operating safely at this time.