Pump noise / cavitation

The pump produces a loud rattling, screaming, or uneven sound during operation. Different from the normal vibe-pump hum.

Why it matters — Often a sign of air in the lines (cavitation), a clogged intake on the reservoir tube, or significant scale buildup restricting flow inside the boiler. Sometimes a pump that's simply reaching end of life.

Good to know

• First step: refill the tank, prime the pump (open the steam tap while pumping), check the intake filter on the reservoir tube for kinks or blockages.
• If cavitation persists with clear flow, descale the boiler. If the noise is constant and rough, the pump is likely failing.

Related: Pumps