rrived onsite for maintenance for one gas fired steam boiler. Requested the customer turn on the thermostats up to heat and confirm operation of the boiler. Turned the boiler off and removed and cleaned all burners and wiped cleaner the burner compartment. Observed significant rust on the burners; looked for leaks but did not observe a leak. homeowner stated they had water issue in the past. Performed a visual inspection of all electrical and inspected all external water components such as automatic water feeder, fill valve, backflow preventer and pressuretrol. Did not observe discoloration in site glass. Confirmed water level on site glass is within specification. Confirmed site glass valves are operational and opened. Confirmed everything is operating and heating properly at this time.