Why Is The Well Pump Humming But Not Pumping

Why Is The Well Pump Humming But Not Pumping?

Why is the well pump humming but not pumping? Is the motor dying? Will it fix on its own? First, turn off the motor. Don’t let it hum continuously; otherwise, it’ll be damaged.

In 90% of cases of humming pumps, the motor fan or the capacitor is defective. Check the capacitance by a tester. If the capacitance is lower than required, go for a new capacitor. In 10% of cases, the motor itself is defective and will need a replacement.

We’ve highlighted everything you need to fix a humming pump below. So, if you have further queries, stay tuned.

Why Is The Well Pump Humming But Not Pumping?

There are a few reasons that are responsible for the well pump humming. They are:

  • Insufficient flow of water dries up the pump. It’s responsible for the well pump humming noises.
  • A leaked foot valve can minimize water pressure leading to humming.
  • Debris might have blocked the impeller and disabled the pump.
  • The capacitor may be busted.
  • Defective motor shaft.

What Are The Symptoms Of A Bad Capacitor?

How will you know if the capacitor is defective? Let’s check out –


Due to a defective capacitor, a pool pump has to run on high amperage and high wattage. Its high wattage consumption is leading to vast heat production.


A capacitor gives the torque you need to speed up a motor. Push the blades manually to spin the motor. If the motor starts functioning, it’s a confirmed diagnosis of capacitor failure.

How To Fix A Humming Water Pump?

You must be worried about the sump pump humming noises. So, how to stop water pump noise? Let’s check it out!

Step 1: Switch Off The Pump

If your sump pump makes a weird humming noise, turn it off at first. It is not going to fix itself. Instead, the coils will burn out.

Step 2: Clean The Fan Compartment

  • First, take a screwdriver to turn the impeller without taking off the cover.
  • If the impeller is tightly jammed, untie the screws & remove the strainer.
  • Clean loads of dust & debris inside the impeller compartment.
  • When the impeller is free to move, turn on the pump.

Step 3: Test The Capacitor

Is the water pump motor still not starting? Check out the capacitor. Without the capacitor, the motor won’t ever have the power to go on.

Tip: Make sure to plug out the pump before opening the capacitor compartment. Otherwise, you may get a spark.

  • Open the top case capacitor compartment. You will notice the capacitance of the existing capacitor written right there.
  • Suppose its capacitance is 25 microfarads. If you plan to go for a replacement, you must go for the same size. However, a 20 or 30-microfarad capacitor is also compatible with it.
  • Now check the reading of the existing capacitor on the multimeter.
  • If the reading is below 20 microfarads (in the case of 25 microfarads capacitors), you need to replace the capacitor immediately.

Step 4: Replace The Capacitor

  • Get the new capacitor.
  • Check its capacitance by setting teslas on either side of the wire.
  • Make sure it matches the required capacitance of the pump.
  • Now connect it with the pump.
  • Lastly, tight up the bolts and reassemble the top case with proper force.

Step 5: Check The Wiring

After replacing the capacitor, the pump is supposed to start right away.

What if the pump is still not kicking in? Then we would like you to look for broken wires. If the wiring is perfect, the motor itself is broken & requires a fix or replacement.


How long does a well pump run before burning out?

The continuous running time before burning out will vary from model to model. You can expect a highly efficient sump pump to run continuously for at least 24-volt hours. In contrast, a mediocre model will run for 6 to 10 hours.

What kind of noise will you hear if the water pump fails?

High-pitched whining noises generally indicate gradual water pump failure. You will also hear a harmonic whining buzz when the operating pulley/belt is loose.

What to check if a Well pump stops functioning?

  1. First, check the circuit breaker system. The presence of a short/ surge will indicate a blown circuit.
  2. Check if lightning has struck the pump during the thunderstorm.

How to reset a well pump?  

  1. Set the reset lever in the start position and hold it until you reach 40 PSI.
  2. Now the lever will automatically return to the auto position.
  3. The pump will keep functioning on cut-out 50 to 60 PSI settings until it completely shuts off.

Why is the flow rate of my pond pump slow?

The pump rate can be slow due to the –

  • Air leakage.
  • Dirty filters and pump basket.
  • Accumulation of debris inside the impeller.

Final Words

Is your well pump humming but not pumping? Don’t panic. Once you diagnose the defect, it’ll be a piece of cake to sort it out. We believe by now you’re well aware of the most probable diagnosis of your humming pump. So, be ready with the screwdriver and tester and fix the water pump right away!

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