The short answer for these models
The question worth answering is not how loud it is but what the sound responds to. A noise that stops when you press the cabinet is resonance, one that changes with the door is a fan, and one that answers to neither is the only kind worth a visit. Where this departs from the brand-level page is the ranking. A built-under cabinet has to shed its heat through one small grille, so anything that restricts that grille shows up as a fault long before it would on a freestanding unit, so on a BUF unit the clearance and condenser checks lead.
How this shows up
- Before the list: which of the BUF forms is in front of you — Look at how the unit sits. A cabinet in a cut-out breathes through one grille, and that grille joins the suspect list ahead of anything inside the machine.
- Sharp cracks or pops at intervals — They come in bursts after a temperature change rather than continuously, which is how you tell them from a mechanical fault.
- A scraping or a knocking you can feel through the floor — You can feel it through the floor as much as hear it, which is a different class of problem from a rattle.
- NEAR MISS — the noise arrived with the cabinet going warm — Then the noise is a symptom of the cooling fault, not a separate problem, and the page about a unit that will not cool is the better one.
Causes, most likely first on this family
- The compressor or its mounts — Low down because a compressor that is genuinely failing is uncommon next to everything above it, and because the sound it makes is distinctive. This is where the order departs from the brand-level page: on the BUF models the construction settles it, so the clearance and condenser checks come before the checks that lead anywhere else.
- The defrost timer or a solenoid clicking — On the list only because it is reported so often: a periodic click is a control doing its job and it needs nothing done about it.
What to check first, and why that order
- First — level the cabinet and check what it touches — Rock the cabinet corner to corner before listening to anything. Any movement at all is worth removing, because movement is what turns vibration into noise. On these models this is the step the construction changes: the answer only tells you something once you know which form the unit is.
- Second — clear the top, the back and the shelves — Loose glass and plastic are the cheapest cause of a convincing rattle, and clearing them takes a minute.
Before you open anything
Safety
Pull the plug or drop the breaker before any panel is disturbed, because a capacitor can hold a charge after the power is off. Keep hands clear of fan housings while the unit is live: the door switch can bring a fan up to speed the instant the door shuts. Empty the cabinet before you move it and take the weight with help, since a full refrigerator does not stop once it is moving.
Where the owner job ends
Call once the cabinet is level, the top is clear, the gap behind it is honest and the sound is still there. Call sooner if it is a grind or a knock rather than a buzz, or if it arrived in the same week the cabinet stopped holding its temperature. Say whether the sound changes when the door opens; that one answer narrows the visit before anyone sets out.
The other symptoms covered for this family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
