Charles Austen ET100AO Pond Air Pump

Charles Austen ET100AO Pond Air Pump

The Charles Austen ET100AO Pond Air Pump is an alarm output version of the Charles Austen ET air pump range, designed for systems where reliable airflow and external fault warning are both important. It is suitable for pond aeration, koi filter aeration, aquaculture systems, septic systems and sewage treatment plants.

The AO version includes the low pressure alarm used on the A models, with a buzzer and LED warning light, but also adds a 230V output cable for connection to an external alarm panel, beacon or warning device. This makes it useful where the pump is fitted away from the house, inside a treatment plant area or in any installation where a remote warning is preferred.

A and AO models are generally used in sewer, septic and sewage treatment applications because the pump may be tucked away and a failure may not be obvious day to day. They can also be used on ponds where the owner wants extra peace of mind, particularly on koi ponds, moving bed filters and systems that rely heavily on constant aeration.

Key features

• Built in low pressure alarm with audible and visual warning
• 230V output cable for connection to an external alarm panel or beacon
• Ideal where remote or external fault signalling is required
• Reliable continuous airflow for ponds and sewage treatment systems
• Oil free air delivery for fish, filters and aerobic bacteria
• Weather resistant casing for indoor or outdoor installation
• Compatible with Charles Austen service kits

Technical overview

• Model: Charles Austen ET100AO
• Product type: Oil free linear diaphragm air pump with alarm output
• Maximum airflow: 100 litres per minute at 0.11 bar
• Power consumption: Approximately 105W
• Power supply: 220V to 240V 50Hz
• Connector size: 18mm
• Noise level: Approximately 45 dB(A)
• Dimensions: 238 x 196 x 177mm
• Weight: Approximately 8.5kg
• Alarm output: Built in alarm plus 230V output cable for an external alarm panel or beacon
• Common uses: Pond aeration, koi filter aeration, septic systems and sewage treatment plants

Compare Charles Austen air pump ranges

Browse the full Charles Austen ET Series, Charles Austen ETA Series, Charles Austen ETAO Series, Charles Austen ETX Series and Charles Austen CP Series air pumps.

What do A and AO mean? Standard ET models provide reliable continuous aeration. The A versions add a built in low pressure alarm with a loud buzzer and LED warning light. The AO versions add the same built in alarm plus a 230V output cable for connecting to an external alarm panel or beacon. A and AO pumps are generally used on sewage treatment plants and septic systems because the air pump may be out of sight and a fault may not be noticed quickly, but they can also be used on pond systems where extra warning is useful.

Equivalent models

• Charles Austen ET100 Pond Air Pump
• Charles Austen ET100A Pond Air Pump

Technical details

• Product: Charles Austen ET100AO Pond Air Pump
• Brand: Charles Austen
• SKU / product code: ET100AO
• Type: treatment equipment
• Check model size, flow rate, connection size and compatibility before ordering.
• Install with suitable supporting equipment and allow access for future servicing.

Maintenance and servicing

Charles Austen state that Pro Series air pumps should be serviced yearly to validate the motor warranty. You can view the correct Charles Austen Air Pump Service Kit options in one place, including genuine replacement diaphragm, filter and valve kits for compatible Charles Austen Enviro ET, ETA, ETAO and ETD models where available. Regular servicing helps maintain airflow, reduce the risk of diaphragm failure and keep your pond, koi or treatment plant air pump running efficiently.

Recommended air diffusers and airline

To get the best performance from this air pump, pair it with suitable large pond and lake air diffuser stations and weighted airline. As a guide, each 10 inch diffuser disc normally works best with around 40 to 50 litres per minute of air. Most single diffuser stations are rated at around 30 to 60 litres per minute, so matching the number of diffuser discs to the pump output helps keep airflow balanced and efficient.

• Suggested diffuser setup: 2 diffuser discs are normally a good match. View the Charles Austen DS2 or Charles Austen DSW2 diffuser station.
• Air manifolds: If you need to split airflow from one pump across multiple airline runs, use the Air Manifold 4mm/8mm/10mm – 2 Way for two runs or the Air Manifold 4mm/8mm/10mm – 4 Way for up to four runs. For Charles Austen air pumps, the 8mm or 10mm outlet options are normally the best choice. The 4mm option is better kept for short, small air stone runs rather than larger diffuser stations.
• Standard sinking airline:
  4mm/8mm Standard Sinking Airline is a practical choice for smaller pond air runs. On Charles Austen pumps we would normally use the 8mm option where possible.
• Heavy duty sinking airline:
  Evolution Aqua Heavy Duty Sinking Airline is the better choice for larger ponds, longer airline runs and high output pumps. For larger Charles Austen pumps, the 8mm or 10mm option is normally the better choice to reduce restriction.
• Super heavy duty weighted airline:
  For long, permanent underwater runs to large diffuser stations, consider our Super Heavy Duty Weighted Airline. Its 12.5mm internal bore helps reduce friction loss compared with smaller airline, and the weighted 30m construction keeps the hose on the pond or lake bed. Use the correct outlet adaptor or manifold and confirm the diffuser connection size before ordering.

Charles Austen recommend that Enviro air pumps are serviced at least every 18 months. On hard working pond, koi and treatment plant systems, regular servicing helps maintain airflow, reduces the risk of diaphragm failure and supports the manufacturer warranty requirements. Service kits are available for the main ET, ETA, ETAO, ETD and ETX models where applicable.

If you are unsure which service kit suits your pump, contact us and we can help match the correct kit to your Charles Austen model.

Complete your Charles Austen aeration setup

A good aeration system is not only about choosing the air pump. Airline size, diffuser choice, manifold layout and routine servicing all affect the real airflow that reaches the pond. Use the links below to build a complete system rather than buying the pump in isolation.

• Browse the full Charles Austen range
• Browse pond air pumps
• Charles Austen air pump service kits
• Large pond and lake diffuser stations
• Standard sinking airline
• Heavy duty sinking airline
• 2 way air manifold
• 4 way air manifold