Sevicing includes checking blower pressure and changing filter, checking over all internal pipes in the tank, checking over liquid pump and non return valves. Opening manholes to ensure liquid is entering tank unobstructed and draining out to percolation area. Checking all tank covers and door latches and notifying customer if anything needs replacing.
Most common callouts are to replace aeration blowers in tank . This can be detected by bad odours arising and failure to hear blower running.
Another callout can be failure of liquid pump. This can get more serious if not detected early. Some systems have high level alarms and buzzers but if not you may not realise anything is wrong until the system backs up and the toilets, showers etc. won't drain properly.
