Well Pump Making Noise — What Each Sound Means

Well Pump Noise Diagnostic Guide

🔴 Rapid Clicking (Every Few Seconds)

Cause: Pressure switch short cycling — the pump is turning on and off every few seconds.

Source: The clicking sound comes from the pressure switch contacts opening and closing rapidly.

Fix: Almost always a waterlogged pressure tank. Test the Schrader valve — water means replace the tank. If air comes out, check pre-charge pressure (should be 2 PSI below cut-in).

🔴 Humming Without Starting

Cause: Motor receiving power but unable to start spinning (locked rotor).

Fix: Turn pump OFF immediately — check capacitor first. A domed/bulging capacitor = replace it. If capacitor is fine, check for seized impeller or low voltage.

🟡 Grinding or Rattling

Cause: Sand or sediment being pumped through impeller, or worn bearings.

Fix: Check water for sediment. If sand is present, pump may be set too close to well bottom. Worn bearings indicate pump is near end of life.

🟡 Banging Pipes When Pump Starts

Cause: Water hammer — pressure surge when pump starts into empty pipes.

Fix: Almost always a waterlogged pressure tank with no air cushion. Replace or recharge the tank. A water hammer arrestor on the supply line also helps.

🟡 Squealing or Screeching

Cause: Worn pump bearings or cavitation (pump drawing air).

Fix: Bearing wear requires pump replacement. Cavitation may mean low well water level or air leak in suction pipe.

🟢 Normal Sounds

A healthy above-ground jet pump produces a steady motor hum during operation. A healthy submersible pump is nearly silent at the surface — you may hear water flowing but not the motor. Pressure switch clicks once at cut-in and once at cut-off are normal.

Frequently Asked Questions

Why is my well pump making a clicking noise?

Rapid clicking from the pressure switch area means the pump is short cycling — turning on and off every few seconds. This is almost always caused by a waterlogged pressure tank (failed bladder) or incorrect pre-charge pressure. Test the Schrader valve on the tank with the pump off and pressure released.

Why does my well pump make a humming noise?

A hum that stops after a few seconds usually means the thermal overload tripped — the motor is overheating. A continuous hum with no water means the motor is locked rotor — trying to start but cannot. Check the capacitor first (most common cause of locked rotor hum) and turn the pump off immediately to prevent motor damage.

What does a grinding noise from a well pump mean?

Grinding from a well pump indicates worn bearings or sand/sediment going through the pump impeller. Sand grinding is abrasive and will destroy the pump rapidly. Check for sand in your water — if you see sediment, the pump may be set too close to the well bottom or the well screen has failed.

Why does my plumbing bang when the well pump starts?

Banging pipes when the pump starts is water hammer — a pressure surge caused by water suddenly rushing into empty pipes. This is worse when the pressure tank bladder has failed and there is no air cushion to absorb the pressure wave. Replacing or recharging the pressure tank typically eliminates water hammer.