Water out · 16 of 21
Loud Buzz When It Drains
A hard buzz through the last part of the drain, long after the water has gone.
| What you can see | What it usually is | Whose job |
|---|---|---|
| A buzz that starts partway through the drain and ends with it | The tub is already empty and the pump is turning on air for the remainder of the timed drain | Often nothing — a listen, not a part |
| A rattle or a knock under the floor as the drain begins | The hose is unsupported along part of its run and slaps whatever it is lying against each time the pump kicks in | Ours |
| A buzz with water still standing in the bottom | Something is lying across the pump inlet and the impeller cannot get a bite on it | Ours |
| A high whine instead of a buzz, and a slow empty | The impeller is worn or loose on its shaft and is slipping rather than shifting anything | Ours |
A drain pump makes almost no noise while it has water to move, because the water damps it. What you are hearing is the same pump running on air, and a long flat run leaves it doing that for most of the drain. Viking Repair Denver listens to the whole cycle before condemning a pump, on (303) 729-0972.
A pump that is moving water is quiet. Take the water away and the same pump becomes a small motor bolted to a plastic housing, and the housing tells the entire cabinet about it.
Why the noise outlasts the water
The drain runs for a set stretch on every cycle, and that stretch has to be long enough for the worst run the machine might be plumbed into. Downtown it very often is: a hose that leaves the appliance, crosses half the floor of a converted warehouse and only finds a stack somewhere near the core. Once the tub is empty the pump carries on turning anyway, and from that moment it is beating air. That is why the buzz arrives towards the end of the drain rather than at the start of it.
What a buzz on its own is worth
Not a great deal, provided the tub empties. A pump gets condemned on how it turns, what it reads and whether it clears the sump in the time it is allowed — never on volume alone. So the first move is to open the door while the noise is happening and look down. Water still standing there with the pump howling means a blockage or a worn impeller, and that is a genuine job. An empty tub and a loud last stretch is a machine doing exactly what it was built to do in a building nobody designed it around, and the honest answer is to leave it alone and spend the money where it buys something.
What to try before anyone drives over
- Open the door the moment the noise starts and look at the bottom of the tub. A noisy pump over an empty tub is a different fault from a noisy pump over a full one.
- Lift the filter out, rinse it and look for a chip of glass or a fruit stone. Grit at the inlet changes the note the pump makes.
- Stand still and work out whether the sound is coming from the machine itself or from the run behind the cabinets. A hose that drums is not a pump that is failing.
That is as far as it goes without tools. If it is still wrong, call Viking Repair Denver on (303) 729-0972 and say whether the tub was already empty when the noise began — it is usually enough to know which part is coming on the van.
Every symptom, grouped by what you can see Water in, water out, cleaning, power and the door — the whole library on one page.
Clifford Nakamura
- Written
- On the van
- Service technician — controls and intermittent faults
- Years at it
- 22 years in the trade