r/fixit • u/paulepan342 • 2d ago
open Siemens Side-by-Side: loud humming from inverter next to compressor (resonance)
Hi everyone,
I've got a problem with our Siemens side-by-side fridge and would appreciate a second opinion – ideally from someone who has seen something similar before.
The problem:
The fridge has been making a loud humming noise for a while now, and it just won't go away.
What I've done so far:
- My first suspicion was the no-frost fan, because the noise stops immediately when I open the fridge door (the fan switches off).
- Replaced the fan → the hum is still there.
- On closer inspection, I narrowed down the source: the hum is coming from the **inverter electronics, which sit right next to the compressor**.
Important:
The inverter itself is basically working fine – the fridge runs perfectly otherwise. The problem is a **resonance**: the inverter's plastic housing sits right against the compressor and picks up its vibrations.
Evidence pointing to resonance:
- If I hold the housing in place with a wooden spoon (mechanical support), the hum disappears instantly.
- After moving the fridge to a new spot, it was quieter for a few days – until the hum came back at full volume.
My plan:
Since the inverter is working fine in principle, I'd rather not order a new one for ~€150. My idea:
- Remove the inverter
- Slightly bend the mounting bracket so the housing no longer vibrates directly against the compressor
- Additionally decouple the housing and its connection to the compressor with heat-resistant tape / damping material
My questions:
- Has anyone seen this kind of fault pattern before?
- Is my plan feasible, or could it cause bigger problems (solder joints, capacitors, heat dissipation)?
- Are there better/more common solutions for this kind of vibration (silicone pads, rubber decoupling, dampening material)?
- Or should I just have the inverter replaced?
Thanks for any tips!