Signs that your air filter needs changing
Some sewage treatment systems work by treating effluent through aeration via a remotely-sited blower. These blowers contain air filters that require annual changing to ensure the blower remains efficient and operational.
Filters should be regularly checked by removing the blower housing - they can be brushed to clean but should also be changed every year. If the blower is running hot or at a high pressure, this could indicate filter blockage.