Newly installed sump pump sitting in a basement sump pit

Sewage ejector pump runs constantly or cycles with no fixture use

Constant running means either the switch thinks the level is high or water really keeps arriving. Check for a stuck or tangled float, a leaking check valve sending the discharge column back into the basin, a running toilet or leaking fixture, and groundwater leaking into the basin. A pump left running wears out fast.

Single source ~60 min moderateBrands: All

Before you start

Raw sewage: gloves, eye protection, disinfect afterward
Sewer gas (H2S): ventilate; do not lean into an open basin
Never enter the basin (confined space)
Lock out the pump circuit and close the discharge valve before opening the lid

Diagnostic steps

Unlock all 7 steps with expected values

Full library + AI assistant for $34.90, one time.

Get lifetime access

OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

More sump & well pumps guides

Guide · Sump / Well Pump

Well pressure switch chattering or clicking rapidly

Chatter happens when the switch sees pressure bouncing around its set point. The usual causes are a plugged sensing port or nipple, a waterlogged or low-precharge tank, a switch mounted far from the tank, worn contacts or a differential set too narrow. Chatter burns contacts fast and stresses the motor, so fix it the same day.

8 steps ~45 minmoderate

Guide · Sump / Well Pump

Jet pump loses prime or runs without building pressure

A jet pump only works when its housing and suction line are full of water. Lost prime almost always traces to an air leak on the suction side, a leaking foot valve or check valve, a clogged foot-valve screen, or a well that has drawn down. Fix the cause, then re-prime; repeated priming alone just burns pumps.

7 steps ~60 minmoderate

Guide · Sump / Well Pump

Well pump hums, won't start or trips overload: control box test (3-wire)

On a 3-wire submersible, the start capacitor and relay in the control box are the most common surface failures and can be tested with a meter. First confirm power through the pressure switch, then test the box. If the box is good or the system is 2-wire, the problem is down the well and goes to a well contractor.

8 steps ~60 minadvanced