The hand test: vibration or a failing pool pump?
Updated : · Piscines VP
With the pump running, put your hand flat on top of the motor and press lightly for a few seconds. If the noise drops, the pump is vibrating on its surface: fixable without a repair. If nothing changes, the noise comes from inside the pump.
It’s the first thing we do at every customer’s home when a pump is too loud. It takes 10 seconds and no tools.
How to do it
- Dry hands. Don’t do it standing in water or in the rain.
- Pump running at its usual speed.
- Put your hand flat on top of the motor (the round part, metal or plastic).
- Press lightly, as if holding the pump down, for 5 seconds.
- Listen for the difference. Ask someone to listen from farther away, for example from the deck or a bedroom window.
Don’t touch: the back of the motor (there’s a fan), the wires, the electrical box, the timer.
How to read the result
| What you hear | What it means |
|---|---|
| The noise drops a lot or disappears | Vibration. The pump is shaking its surface. Nothing is broken. |
| The noise drops a little | Mostly vibration, plus some normal motor sound. |
| No change at all | The noise comes from inside: bearings, cavitation or debris. |
| The noise changes when you touch a pipe | The plumbing is carrying the vibration. |
Why it works
Your hand adds weight and absorbs part of the motor’s movement. If the noise came from a worn part inside, your hand wouldn’t change anything. If it came from vibration passing into the slab or shed, it drops right away.
Next steps
- Vibration: read Noisy pool pump and Where and how to install your pump.
- Inside noise: read Worn bearings and Cavitation.
If the noise drops when you put your hand on it, SOURDINE is for you. Launching for the 2027 season. Get notified →
Frequently asked questions
Is it dangerous to touch a running pump?
The top of the motor is safe to touch with dry hands. Never touch the back of the motor (fan), the wires or the electrical box, and never open the pump without cutting the power.
The motor is very hot, is that normal?
A motor feels warm after running a while, that's normal. If it's too hot to keep your hand on for a few seconds, turn the pump off and have it checked.
Not sure of the cause? Take the 2-question diagnosis →
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