Pump troubleshooting
My pump has become noisy
Pumps make some noise, but a change in the noise is worth listening to. The kind of sound often points straight to the cause.
What the sound is telling you
- A grinding or rumbling that gets worse over time usually means worn motor bearings.
- A gravelly, marbles-in-a-can sound while running is often cavitation, the pump struggling to draw water.
- A rattle or buzz can be loose mounting or pipes.
- A loud hum with little or no water movement can be an electrical or start fault.
What to check
- Confirm it’s the pump and not the pipes (see the water hammer guide).
- Check the pump is bolted down firmly on a solid base, with any anti-vibration mounts in place.
- For a gravelly cavitation sound, check the suction side. A blocked inlet, a partly closed valve, a clogged filter, or too small a suction line makes the pump starve.
- Grinding bearings generally mean the motor needs a service or replacement.
When it’s the bearings
Bearings are a wear item. A pump that has run for years and developed a steady grinding or rumbling that rises with speed is usually telling you the bearings are on the way out. On many pumps that’s a service job; on others it’s the point where replacing the pump makes more sense than repairing it.
Common questions
Can I keep using a noisy pump?
A minor new noise, keep an eye on it. A loud grinding, or a hot pump that hums but won’t move water, stop using it and investigate, as you risk further damage.