Strange Noise | Fronius Symo

Hi All,

This is a ‘Fronius’ question. Last weekend my inverter started making a very strange noise & ‘no’ it wasn’t the internal fan(s). The 5kW inverter was outputting around 3kW at the time. My wife recorded the sound on her iPhone and it’s available at

I contacted my installer as the unit is still under warranty. They said they unless there is an error code showing or an obvious ‘fault’ I would have to pay for the call-out. I declined their offer.
Has anyone heard a similar noise before? The noise only continued for a few minutes and then stopped. I have heard it again a few days later. To me it sounds like ‘stressed’ capacitors.

I’m interested if anyone else has had a similar experience.


1 Like

Yes. Have you updated the firmware recently? I updated my symo firmware yesterday and am getting a similar sound today. Several others on whirlpool reporting similar.

1 Like

Hi @tinkywinky in fact ‘yes’ I updated the firmware to 3.16.7-1 a few days earlier.

I’ll take a look at the whirlpool posts… [EDIT]I’m quite certain that the noise isn’t from the fans as I’m used to that and it doesn’t sound ‘mechanical’ - like a failing bearing[/EDIT]

I agree. Fan sounds normal but there is a high pitched background sound. My theory is that it is coil whine or something like that.

@grannos, did you update your firmware in the last few days to fro32370.upd? A few us updated and are seeing a similar issue, as discussed from here.

Hi @bulletmark. Yes, I’ve updated the inverter’s firmware to fro32370. I just realised that the 3.16.7-1 that I referred to above relates to the Datamanager card and not the inverter.

Some have managed to stop the ticking noise by cycling the inverter off/wait/on, but others not so lucky. There seems to be at least 2 noise issues after this update - this new ticking sound and a different whine to the usual occasional fan noise. Some have mentioned the noise is only obvious or worse at around 50% PV generation.

Hi. I have since power-cycled my Fronius inverter. Despite cross my fingers the noise hasn’t gone away. I’ve heard at several intervals. There’s no obvious pattern to the noise occurring other than the inverter is actually inverting at the time ( I have not heard any strange noise(s) after dark - I am also less likely to be outside too ). The temperature here in Perth has been quite mild. I do log the Inverter Temp too. The inverter fan noise has been fairly low as compared to the middle of summer on a 40C day. All very odd.

All. I have an update. After contacting the installer, who didn’t really want to know, I contacted Fronius directly. After some mucking around trying to send them the audio files they ( Fronius ) have advised me that they have escalated the problem.

I noticed yesterday ( PM ) that my inverter’s firmware was being changed - not by me. The firmware has been rolled back to fro32071.upd

The strange noise that I originally reported had continued off an on up until the point that the firmware was altered. I have not heard the noise since the firmware downgrade but it’s still a bit too early to be sure.

Stay tuned.



Fronius confirmed that they rolled back my inverter’s firmware to the previous version fro32071 from version fro32370. They also stated that the newer version was responsible for the odd sound in some instances.

Since the firmware was rolled back I have not heard any odd noise(s) coming from the inverter.


1 Like

Good to hear (boom-tish!) you got a rectified outcome from the supplier.

I know that sound, its the Londen metro at Trafalgar Square


In the continuing saga. Fronius have released fro32410.upd of the firmware. This versions supersedes the troubled version ( see above ). After checking with Fronius that it would be ‘safe’ to update my inverter from fro32071 I went ahead and did so.

Alas the strange noise has returned although it sounds slightly different to before. It still sounds like distressed electronic components. I have advised Fronius of the problem and provided them with an mp3 recording of the noise.

Stay tuned.


Following my email to Fronius and supplying them with a newer mp3 recording they have [ remotely ] changed the inverter’s firmware from fro32410.upd to dcr32420.upd [ Yes dcr32420.upd ]. The strange noise has disappeared - again.


1 Like


Another update.

This morning I walked by my inverter and could hear that the weird / strange noise had returned. I have recorded the sound on my phone. Before emailing Fronius I checked the version of the firmware in the inverter. I found that it had been updated late last night ( WST ) from dcr32420.upd to fro32450.upd.

I will let you know what Fronius have to say about the matter.


Thanks for the reminder for me to go to my inverter settings and set “Allow automatic updates” to off!


The update to fro32450.upd [ The latest update as of the time of writing this ] has caused the same noise problem. Fronius have rolled the firmware back to fro32071.upd

Not making much headway here!


My Symo is still on fro31331.upd

Re the Primo 3kW
Same issue here with the odd noise it sound like one of the high frequency coil transformers has changed freqency ?
New update 482 is availble for updating now.
Will report if fixed the issue?
Only started when it had an update sometime back.

Hi. Fronius upgraded the firmware of my inverter to fro32482.upd on 06DEC2021. I am happy to report that so far so good - I have not heard any odd noises coming from my inverter.

However it has been extremely hot here so I haven’t been outside as much as normal and the inverter fans have been very loud and would tend to mask any underlying noise.

We are experiencing milder weather now, thank goodness so it will be easier to hear if anything happens. If I don’t hear any weird noised in the next few days I’ll assume that the problem has been finally fixed.