Fox ESS UK Reviews 112

Hi, I have been working with Fox ess for many years, and all I can say I wouldn’t use any other manufacturer, I fully recommend Fox-ess, also Ben never lets me down when required, a fantastic Engineer.

Tenical support from Ben was second to none, on site when requested. Would recomend!

I was most impressed with Alex, technically, with her command of English, and her demeanour.
She solved my inverter problem efficiently.
She is a credit to Fox.

Had my system installed at beginning of Feb
Had 2 lots of panels with 2 Fox inverters 3kw & 3.6kw.
Became apparent that the 3.6kw inverter with a single string was producing less power that the 3kw inverter with two strings even though the single string has a greater number of panels!!
Looking at the output it was clear that the 3.6kw was clipping the current @3kw for hours during the day, took screen shots, and asked FOX ESS UK what was wrong, one of the untechnical staff told me the system was working fine, when it quite clearly wasn’t, a premonition of what’s to come!!
So to test out if it was panels (FOX UK’s new excuse) Bought second had 4kw inverter of another make and fitted on the single string and immediately it produced 4.1kw, told FOX and there didn’t even respond, obviously don’t like being proved wrong or just ignore real problems!!
After reading some forums from Auz (much larger user base), many users have reported string limits.
Put the 3.6kw inverter on the split stings and it will sit producing 3.6-3.8kw when the sun is out without clipping. Pretty conclusive that there is an individual string limit that the UK team don’t know about, nice product knowledge!
Then found out today that FOX UK sent out new data sheets to their installer base shows there ARE single sting limits of all of their inverters.

So a customer worked out limits that FOX ESS UK tech team denied.
Many customers may be losing power&money if they are on a single string set up and are not aware of the limits clipping their output, this is pretty poor by any standard.

Not had a sorry or acknowledgement from the UK distributor, says all you need to know about them.
Will not be fitting any more of their systems to another one of my houses.
Shame as the kit its self is OK, just the UK team behave like mindless box shifters, who don’t care.
In Response to FOX UK response, you have already had all the inverter serial nos. screen shots of the inverter clipping, and even sent you details of the panels, the irradiance each day in Kw/mtr2 taken from the middle of the panels. and just got ignored. i have asked you to contact me and left messages, Last was an email on the 21st March, i sent 5 emails from 14th to the 21st March, the last 3 had no reply. and phoning is impossible as it goes to an answer system where no one returns the calls.

Working with fox we were having a few issues which we could not fix over the phone, they got us in touch with Ben who attended site in a professional manner and his training was second to none to help us understand the system as he does. He is a top notch engineer and great bloke.

I have just installed the EQ2900 ESS, from the ground up what a simple process it was putting the modules together. This was to replace a legacy battery Fox ESS model HV2600 that had developed a BMS firmware issue in a retired model where replacement parts were no longer available. Fox ESS UK stepped up and provided a new replacement system that resolved the issue completely.
It plugged straight into the existing AC1-5.0-E Inverter and after powering it on worked perfectly. What more can I say? Service and Support with a capital S's!

Many companies live and die at the hands of a few people. On this occasion I thinks it’s safe to say that Fox shone on account of one such man by the name of Ben Humphrys….

I am a big advocate of Fox and I think they offer price and performance which is hard to beat…

That said, having just experienced a rare technical fault on an installation Fox fell well short of what should be expected of them…..

At the absolute last minute, it was Ben who came to the rescue and saved an installer a negative conclusion to his day,one weekend of anxious waiting for a customer who had already waited too long because of Fox’s somewhat poor response to the situation…

This isn’t the first time Ben has stepped up either and it is for that reason I 1. Can bring myself to even give 4 stars which on this occasion is more than they derlserve and 2. Feel compelled to give Ben his due props and frankly so should Fox….As an employer, people like this don’t come along often and frankly the rest of you who let me and this customer down on this occasion should seriously take note..

Thanks mate, sincerely appreciated!

Lewis the remote engineer was absolutely fantastic helped me through the process step by step untill the system was fully up amd running could have asked for any better help honestly

I had an absolutely brilliant experience with Fox ESS, and I want to give special recognition to Lewis for his exceptional support. He was absolutely amazing at sorting my issue — genuinely going out of his way to help me with the situation I was in.
Lewis took the time to understand the problem properly, kept me updated throughout, and made sure everything was resolved as quickly and smoothly as possible. Customer service like this is rare.
Even better, the replacement unit was dispatched in under 7 days, which exceeded all expectations.
Huge thanks to Lewis and the Fox ESS team for delivering such outstanding service. Truly five‑star support

Great installation, already saving 60% and can see from the app where I can save a further 20%.

This is an update from a review earlier in the week which I gave 1 star because I couldn't monitor the solar production from my solar panels. This problem lasted about 2 weeks and I had been given conflicting information on how to fix the problem when I could get in contact with Fox.Yesterday I received 2 new data loggers and Craig, the Technical & Product Director at Fox, talked me through the whole setting up process, taking his time and explaining the setup. I can now
monitor the solar production again.Craig also apologised
for the way the Customer Support had handled the problem. I'm very appreciative in the way Craig handled
the problem.

Lovely support people, a shining example of how it should be. Particular thanks to Bernard and Gurush, but everybody there is lovely.

Hi, I would just like to say thank you to a very kind gentleman at Fox for sorting out my problem it was done swiftly professionally. I cannot complain about the service that I received. I would recommend this product now. thank you.

Lewis was able to resolve my technical query in less than 5 mins, after I'd been struggling to diagnose the issue for more than an hour. Can't speak highly enough and hope to deal with him again if I run into troubles in the future.

Well all I can say is don't let people tell you that Fox is budget equipment !!

Great quality and brilliant piece of kit !

EQ4300 / KH9 inverter

Very happy and soaking up the solar very well !!!

Kai Xu from the Fox ESS UK team was absolutely excellent from start to finish.

I had an issue with the WiFi dongle on my system and Kai was incredibly patient while guiding me through all the testing step by step. He made everything easy to understand and didn’t rush anything, which I really appreciated.

Once we’d identified the problem, he arranged for a replacement dongle to be sent out for next day delivery, and everything is now working perfectly.

Fantastic service, great communication, and a real credit to the company. Thanks again Kai!

Excellent advice and support from Lewis Cooper, solved our issues in minutes
So pleased with level of support I will be changing my specification for our next installation to FoxESS

Had a Fox ESS inverter and battery installed in 2023 which worked perfectly for a couple of years before developing a fault with the grid power readings.

Although it took a bit of time and discussion to establish that it was definitely the inverter that was at fault, once agreed, the inverter was swapped out quickly by Lewis at Fox ESS UK.

Overall I'm very happy with the product, and it's good to know that it's backed by solid UK support.

Samantha could not have been more helpful. She was incredible as I was asking so many stupid questions and she could have not done more to help. Thanks so much

I have no problem with the Fox kit which has been used in my solar setup. However, the Fox software used to manage and monitor the setup is a total disaster. Often resulting in the poor end user having to reconfigure their software and setup in order to restore their system to where it was before. The solar installers are also often impacted by these changes and as a result are not able to offer their clients an adequate support service. As for support and communication from Fox themselves, this is almost non existent and they totally useless. A Fox setup is great until they do a software upgrade which doesn't go according to plan (which is very frequent), then you are pretty much on your own.
My advice to anyone looking to get a Fox setup installed would be to look elsewhere.

Update 11-Mar-2026 16:50
Hello Fox ESS UK, first of all thank you for taking the time to respond to this review and the ticket I raised with you earlier today. However, the communication from Fox to your global end user base when you have problems like this leaves a lot to be desired. Something like a simple and timely communication on your support portal acknowledging you have an issue would at least save many of your end users the stress of trying to work out what is wrong with their solar setup. Of course all software platforms will have issues at some point, but the way in which Fox keeps its end users and installers informed is woefully inadequate. I would also have to say that the manner in which Fox has managed its update rollouts over the last few month has also been well below standard. There have been a number of incidents similar to this one recently which makes me question how thoroughly the software or firmware is tested before it is rolled out and whether the roll out / roll back processes are ever tested. Again communication regarding planned rollouts would be helpful to both end users and installers alike. Forewarned is forearmed. Failure to address these issues will cause your user base to loose confidence in you, your reputation will become damaged, you will loose business to your competitors and ultimately your profits will evaporate.