Septic Pump Short Cycles

[John Hill]

Aerobic system.
3 Floats.
Septic pump pushes to 4 sprinklers.
Little Giant septic pump replaced in 2021.

About 6 months ago I noticed the pump would run for about 60 seconds, stop, wait 5 minutes, and repeat.

I thought it was a bad float so I replaced the middle float.
No change.

I just pulled the pump and took off the PumpSaver filter screen, thinking the flow may be limited, and the pump tripping due to thermal protection.
No change.

I'm guessing the next step is to put an Amp meter on the pump cord to see if it's pulling too much power.
I figured it if was then the breaker would trip, but the breaker has never tripped.

Any other ideas or troubleshooting steps you suggest?

 

[RS]

You don't mention the most important thing, is it pumping out the effluent? That is bad for a pump to start/stop so often, but maybe just adjusting the switch would help. Possibly reducing the discharge to 2 sprinklers would make the pup run longer at a little higher pressure, and run cooler. Possibly the sump pit is too small for the pump, causing it to short cycle. I think when ours starts it runs about 3 minutes, and then is off until more effluent runs into the pit, maybe minutes, sometimes days.

 

[wpns]

What was the normal run cycle before you replaced it? And what was the normal run cycle after you replaced it? It’s possible the pump is too big and it’s clearing out the sump pit too quickly.
How much water do you have running through the system? Is it possible there is a toilet running or some thing like that?
I also, is it possible that a check valve has failed?