Sewage Pump Fault Finding Guide

High level alarm sounding

A high level alarm usually means the chamber level is higher than normal or the pump station has not emptied correctly. Reduce water use where possible, photograph the control panel lights and call for support. Do not enter the chamber. Common causes include a failed pump, stuck float switch, blocked impeller, closed valve, control panel fault or rising main restriction.

Sewage pump not running

If the pump is silent, check only what is safe and visible: panel power, alarm indicators, isolator position and whether there are any fault lights. Do not open live electrical equipment unless qualified. Likely causes include float failure, overload trip, motor failure, control fault, cable issue or seized pump.

Pump tripping electrics

Repeated tripping should not be ignored. Do not keep resetting the breaker. A sewage pump may trip due to water ingress, motor failure, a jammed impeller, damaged cable, failed capacitor, overload condition or panel fault. Send a photo of the control panel and describe what trips and when.

Pump runs but does not empty the chamber

If the pump can be heard running but the level does not fall, the issue may be a blocked non-return valve, damaged impeller, air lock, discharge pipe restriction, incorrect rotation on a three phase pump, or a pump that is no longer suitable for the duty.

Information to send before attendance

Helpful details include site postcode, pump make and model, serial plate photo, chamber photos from outside, control panel photos, alarm status, whether the pump runs, whether electrics trip, and whether the system serves foul sewage, grey water, a basement, a package pump station or commercial wastewater.

Safety note

Sewage pump chambers can contain contaminated water, gases, moving equipment and electrical hazards. Do not enter confined spaces, do not handle live electrical equipment and do not remove covers where it creates a fall or contamination risk. If in doubt, call Alton Pumps for advice.