Aerobic Septic System Air Pump Not Running (Reset Septic System)

Aerobic Septic System Air Pump Not Running

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If the air pump or aerator of the septic tank isn’t working and you don’t know what to do next, you are exactly at the right place.

Note: If you interested to get new check the best septic system air pump

There may be many reasons why the pump isn’t functioning properly, we will discuss troubleshooting each of the problems.

Stay with us to know more about the septic tank aerator troubleshooting.

The septic aerator is the most critical part of the septic tank. The function of the septic aerator is to maintain a level of oxygen gas within the tank.

It provides oxygen to the bacterial colonies by pumping the fresh air from the outside environment towards the septic tank.

Aerobic Septic System Air Pump

We are dealing with an aerobic septic system, the presence of oxygen is very necessary for the bacteria to perform their function well.

If your air pump stops working, the bacterial respiration transfers to anaerobic and the original functionality of septic tanks get affected.

So you need to investigate the cause as soon as possible to make the tank back to work.

Types of Air pumps In the Septic Tank

  1. Linear diaphragm and piston
  2. Rotary vane compressors
  3. Regenerative blowers

Location of the Air Pump 

It is located above the ground.


 High oxygen accessibility. 

Working Of Septic Air Pump System

  1. A septic aerator works on the principle of an air pump. It directs the oxygenated air towards the tanks for the aerobic septic system. It pumps air not the tank which modifies the tank into an aerobic environment. 
  2. This aerobic environment activates the aerobic bacteria that utilises oxygen and breaks down solid wastes.
  3. So the air pump is a very necessary part of the septic tank. Without an air pump the septic tank is unable to do its job.
  4. That is why a damaged air pump must be fixed on time to avoid other complications.

Troubleshooting the Septic Tank Air Pump

The septic tank signals when there is any issue. Observe the problem, identify it and solve it. 

When a septic pump stops working, identify problems in the three main areas 

  1. the electrical system
  2. the pump system 
  3. the controls system 

First check the tripped circuit breaker. If the breaker continues to trip then serviced it immediately. 


If the pump stops working and does not respond to any tests then check for the possible cause.

If pumping the effluent is defected, there is a chance of problem in the wiring. Take a multi-meter and check the circuit breaker and wires for any damage.

Aerobic Septic System

Replace the thing that’s creating the problem.

In electrical problems, the air pump may get affected by

  • A blown fuse
  • Tripped circuit breaker 
  • The pump power cord is not properly wired 
  • Poor contact
  • Tightness and corrosion of pump cord cap prongs
  • Small branch circuit wiring to carry the pump load
  • Circuit breaker feeds power from other outlets or appliances
  • The pump motor overload tripped
  • The pump motor overload tripped
  • Connect the air pump to a separate circuit.
  • Thermal overload and shutdown
  • Control panel loose connections 
  • Water tightness. 
  • Defects and wear in the control panel 
  • Burnt or melted components of pump control panel
  • Bad splice connections 
  • Corrosion in splice connection
  • Damaged conduit
  • Damaged wiring in the conduit

Loss of Power

  • Electrical problems are a bit easier to solve. 
  • The power loss to the air pump will automatically stop the pump from working. 
  • Identify the power loss issue and fix it. 
  • If there is a troublesome issue, consult a professional to fix the power issue.

Low Voltage Provided To the Tank

  • The tank air pump requires a Voltage of plus or minus 10% of motor ratings.
  • If the pump isn’t getting the required voltage, it may cause the air pump to stop.
  • Check for sufficient power supply by reading the voltage at the pressure switch.
  • You can also read the voltage through the control box and at any other components through which power is running.
  • You need to contact the energy provider and an electrician to fix the electrical issues if present.


  • Electricity is very dangerous. If you are not a professional and are dealing with electrical equipment, you need to take proper cautions when working with electricity. Safety comes first.
  • Use safety gadgets and plastic gloves.
  • Turn off power supply breakers while testing the components of electrical system. 
  • Remember if you are not 100% confident about your expertise do not perform any test. 
  • Call a professional electrician to get the job done.

If there aren’t any electrical issues, there might be a motor issue with the lift pump.

Electricity is flowing at proper voltage but the pump isn’t working. The reasons are discussed below.

Problem in the Diaphragm

Over time it gets very dry and starts to wear out. It’s the most venerable part of the pump system. 


  • In case of extensive surface damage, quickly repair it.
  • To remove the dryness, lubricate the diaphragm according to the manual guidelines, provided at the time of installation.
  • To ensure the proper working of diaphragm, it is lubricated with standard oils available at your nearby hardware stores.

Damaged or Clogged Filters

  • The air pump may not work because of damaged filters. 
  • A clogged filter will restrict airflow.
  •  When the airflow gets low, no adequate oxygen will be supplied and hence it will slow down the decomposition process.
  • Sometimes the owners of the septic tank are unaware of the system’s aerator filter.
  • The aerator demands new filters over time. These filters are preplaced given while installing the septic tanks. 
  • The filter acts like a blower or a compressor. 
  • You don’t need to clean or fix the filters, all you need is to replace them. 
  • Use the filters according to the retailer’s recommendations.

Diffuser with overloaded grime

  • The diffuser may be overloaded with hardened grime, this provides a barrier in the proper functioning of the air pump.
  • The diffuser needs to be cleaned by treating it with muriatic acid. Open the pump, Disengage the diffuser.
  • Take it out and dip it in muriatic acid. 
  • After dipping, wait for some time.
  • The muriatic acid removes all the hardened grime on the diffuser.
  • Take the cleaned diffuser and engage it back to its place.

Blocked or Bound Impeller

  • To fix the blocked impeller, disconnect the power.
  • remove the air pump from the system
  • observe impeller and shaft rotation
  • If they are not freely rotated, clean the volute and impeller.
  • In case of blockade, remove it properly.
  • This will ensure the pump works back to normal.

Frozen Air Pump Bearings 

  • To fix the issue, disconnect the power.
  • remove the air pump from the system
  • observe impeller and shaft rotation
  • If they are not freely rotated, lubricate the bearing of the column pump.
  • Remer to lubricate the lower bearings.
  • This will ensure the pump works back to normal.
  • If the problem persists, call a professional to replace the bearings.

Sewage Pump Failure

  • To ensure proper working of the air pump, the sewage pump must work well. 
  • If by any means it fails, it will cause the water in the septic system to rise. 
  • This will send a signal to the septic alarm.
  • You have to replace it or repair the sewage pump to restore the functionality of the septic air pump system.

Inadequate Air Pressure

  • The air pump directs the air towards the tank.
  •  If there is inadequate level of air pressure the air pump will stop working. The aerator needs to adequately provide oxygenated air to your septic system. Once the pressure is low the tank will signal out. 
  • This means there is something wrong with the septic system.
  • Maintain proper pressure using useful gadgets to fix the problem and turn the air pump back to normal function.

In Adequate Water Level

  • If the water level is not adequate, Add water to the sump.
  • Now observe the working of the pump after turning it on. You can readjust the control floats and weights of the pump.

 Internal Motor Defect

  • disconnect the power supply
  • Remove the pump
  • connect the pump to the rated voltage
  • After that, actuate the control switch. 
  • You can call a professional to replace the internal motor, for proper functioning of the air pump.
    Damaged or Stucked Float 

The float is employed by the air pump to detect sewage levels. Any damage to the float will cause the pump to stop.

Aerobic Septic System

Other float/control problems may include

  • Obstruction or restraining in the float operation. 
  • A bent float rod  
  • Obstructed float rod by the debris. 
  • Defective float switch 
  • Signs of a defective switch 
  • deformed float switch
  • burned or melted components of the switch
  • black discoloration on the float switch

Most Common Aeration Types

Look for the manual to know about the aeration type your septic tank utilizes.

Type 1. Positive pressure aeration system.

Type 2. Negative pressure aeration system.

Type 3. Pull-up aeration system.

Type 4. Push-Pull aeration system.

Type 5. Manifold aeration system on two bins.

Type 6. Cross flow aeration system.


If your septic tank signals for a defect, investigate the pump for electrical, pump and control issues. Identify the issue and fix it, to run the air pump efficiently.

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