Arrived onsite for maintenance for one gas fired boiler. Requested the customer turn on the thermostats up to heat and confirm operation of the boiler and each zone valve. Turned the boiler off and removed and cleaned all burners and wiped cleaner the burner compartment. Performed a visual inspection of all electrical and inspected all external water components such as the exp tank, fill valve, backflow preventer and the circulator pump. Observed some air in the piping noise, loosened the air vent and let system cycle. It seemed to help. Recommend adding an air eliminator to the system; will send an estimate.
