Ron dealt with a battery issue within an hour on a weekend remotely. Very clear instructions to fix the issue worked first time. Excellent service.
Fox ESS problems & faults
- Free remote diagnostic
- No fix, no fee
- All Fox ESS models
My 90-year-old father-in-law had a solar system installed nearly three years ago that never worked properly and kept tripping out. Neither the original installer nor GivEnergy could resolve the issues, and we were even pushed towards replacing the system entirely when GivEnergy went bust. I contacted Ron at Solar Tech Support via WhatsApp, and within a few hours he had diagnosed multiple faults — including incorrect wiring that posed a potential fire risk. He carried out a home visit in Nottingham for £295 (including parts), fixed everything, completed firmware updates, and ensured the system was fully operational. Since then, it has worked perfectly. Ron was knowledgeable, responsive, and took the time to explain everything clearly. Highly recommended — excellent value and complete peace of mind.
Ron is one of those rare finds - an engineer's engineer. He insightfully and accurately diagnosed the problems with our GivEnergy system, very quickly, which helped get us back on track. We will be using him again!
Sts does a extremely great job. Thank you.
Ron was brilliant. He really tried to help. He spent hours trying to fix our GivEnergy AIO and ultimately it became apparent that it needed parts to fix the BMS management system. As there appears to be no replacement parts available on the market, he gave excellent advice on what options are now available to move forward. He is incredibly helpful and knowledgeable.
Ron was really helpful. He remotely adjusted my battery settings on the same day I contacted him, and at a reasonable price. Great service.
What actually goes wrong on Fox ESS systems
A Fox ESS fault isn't always broken hardware. It can be configuration. In Feed-in Priority, set in Fox Cloud, solar feeds the house first and then the grid, and the battery charges from solar only if the export limit is exceeded, so the battery can sit at low charge. A schedule in Mode Scheduler or a maximum charge level can stop the battery charging (Fox's inverter manual calls timed charging "Force time use"; the app has no mode of that name). A minimum charge setting stops it discharging.
Communication is another theme. A BMS Lost alarm (code 14) means the inverter has lost contact with the battery BMS. Fox's own action for it is to check the BMS cable between the inverter and the battery, and that check is an installer's job. And the 2.4GHz WiFi dongle can drop off Fox Cloud after a new router or a changed WiFi password, and then needs re-pairing; if it won't reconnect, we can set it up on site, from £195. Add grid protection alarms (Grid Volt Fault 26, Grid Freq Fault 27 and 10min Volt Fault 28) when the inverter sees voltage or frequency outside UK limits, Ground Fault and Iso Fault alarms, meter and CT faults, and EPS backup that never worked because the port was never wired.
We start with the Fox Cloud alarm history and the settings, work out whether the problem is configuration, BMS comms, grid or wiring, and tell you straight what the fix is. The remote diagnostic is free, and the remote fix is £125 only if we fix it remotely.
Got an alarm name or number? Look it up in the Fox ESS fault code index, and find datasheets and manuals on the Fox ESS documents page. For who to contact: start with your installer for wiring, commissioning and warranty, reach Fox ESS UK through our Fox ESS warranty guide, or ask us for an independent diagnosis; for a warranty claim, if your Fox ESS installer has gone bust, we can be the Local Installer you appoint to make the claim.
Fox ESS problems and faults we cover
Each topic links through to a step-by-step guide.
Battery not charging or discharging: checks
Fox ESS battery not charging from solar or the grid, or not discharging? Check the work mode, Mode Scheduler and reserve settings in the Fox…
See battery not charging or dischargingBattery offline or BMS Lost: comms fault
Fox ESS battery offline or BMS Lost (code 14)? What the battery alarms mean, what you can check in the Fox Cloud app, and when to call your…
See Fox ESS battery offline or BMS LostEPS not working in a power cut: backup checks
Fox ESS gave no backup in a power cut? Check whether EPS was wired and switched on, the reserve settings and the load, and which jobs need an…
See EPS not working in a power cutGrid voltage, frequency or grid lost fault
Fox ESS showing Grid Volt (26), Grid Freq (27), 10min Volt (28) or Grid Lost (1)? What each alarm means, what you can check and when to tell…
See detailsGround fault & Iso Fault — earth diagnosis
Fox ESS Ground Fault and Iso Fault are two different alarms: a failed ground connection, and low insulation on the PV side.
See Fox ESS ground fault & Iso FaultMeter Lost Fault or code 240, causes and fix
Fox ESS Meter Lost Fault (242) or CT code 240? What each one means and what you can check in the Fox app without opening anything.
See detailsOffline in FoxCloud 2.0 or the app: checks
Fox ESS offline in FoxCloud 2.0 or the app? See if it's the app, the dongle or the system, follow Fox's own checks, re-pair the dongle and…
See Offline in FoxCloud 2.0 or the appMore Fox ESS help
Help with Fox ESS inverters and batteries in the UK: fault codes, Fox Cloud offline, EPS backup and battery alarms. Not affiliated with or endorsed by Fox ESS.
See Fox ESS hubFox ESS inverter and battery alarms by name: Grid Volt Fault, BMS Lost, Iso Fault and more. What each means, what Fox advises, and where app numbers come from.
See Fox ESS fault codesDownload Fox ESS datasheets and manuals for the H1 (G2), H3, EVO and the EP, EQ and ECS batteries, plus quick installation guides for the H3 and H3 Smart.
See Fox ESS documentsFox ESS UK warranty terms by product, the 120-day Fox Cloud rule and who can claim, from the 2026 policies. If your installer's gone bust, we can claim.
See Fox ESS warrantyFox ESS fault questions answered
Need a Fox ESS engineer?
Tell us what's happening with your Fox ESS system. Free remote diagnostic; £125 only if we fix it remotely. We don't set up or diagnose WiFi remotely or over the phone: it's quicker and more reliable done on site.
- No fix, no fee covers remote fixes. On-site work is quoted in writing before we start.
- Emergency response within 4 hours during business hours
- Written report regardless of outcome
We’re busier than ever. Thank you for your patience.
Due to unprecedented demand we’re currently only carrying out on-site work in Yorkshire, and replies are taking up to 7 days. Remote diagnostics continue for the whole UK as normal.
Every message is read and answered, so please don’t send it twice; that only slows the queue.
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Got a solar fault or need a quick answer? Drop us a message and we usually reply within a few minutes. Mon–Fri, 9am–7pm.