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.
Sunsynk problems & fault guides — every common fault covered
- Every common fault covered
- Evidence-led diagnostic paths
- Most faults diagnosed remotely
Tell us what you're seeing — fault code, what Solarman shows, what changed recently, what the battery is doing. We'll identify the fault and give you the fastest path to a fix.
Book your free remote diagnosticSolar not working at all?Independent — not affiliated with Sunsynk Energy.
Ron took me through a diagnostic to confirm my GivEnergy Inverter had a fault. A common one as it turns out with the AC Inverter. As GivEnergy is defunct there is no immediate fix, aside from sourcing 2nd hand replacement. It may be that a fix becomes available over the summer which would make a lot of GivEnergy customers happy (Again)
Very very helpfuland so quick. Made sure that a non expert like myself understood what the problem was and how to resolve it.
What a fantastic service. Had my fault diagnosed within minutes and actually managed to resolve the issue remotely within a few minutes more. This guy is like a “Solar Batman” helping consumers fix their problems using his extensive industry knowledge and expertise. Outstanding service. Thank you so much.
Our SolarEdge PV system with LG batteries had its first hiccup after 8 years of hard work. The Inverter failed. Fortunately I found Solar-Tech-Support who diagnosed the problem very quickly, ordered a replacement unit and fitted it shortly after we received the unit from SolarEdge. Very thorough and professional approach. Thank you, a solid 5 star recommendation.
Called back within a day and gave good advice.
Battery charging & discharging problems
The most common Sunsynk call-outs. Nearly always a configuration issue — TOU schedule, grid charge enable setting, or SoC threshold — that can be resolved without a site visit.
Charge window set correctly in Solarman but battery stays at minimum SoC. Covers TOU schedule errors, grid charge enable being off, SoC minimum threshold, and Octopus tariff clock offset issues.
See Sunsynk-specific guide →Sunsynk integrates with Octopus Agile, Intelligent, and Go but the TOU schedule must be precisely configured. Common issues: charge windows offset by BST/GMT, grid charge enable toggle, SoC target not high enough.
See Sunsynk-specific guide →Battery shows charged but the house draws from the grid at peak times. Usually a discharge schedule configuration error, SoC minimum set too high, or an EPS battery reserve threshold preventing normal discharge.
See diagnostic guide →Solar output & grid connection faults
Low or zero solar generation, unexpected grid imports, and EPS backup not activating during a power cut. Check Solarman for DC input voltage and error codes first.
Sunsynk hybrid inverter powered but showing zero or low generation. Check Solarman for DC input voltage readings. Common causes: DC isolator tripped, string fault, grid overvoltage curtailment, or export limit active.
See diagnostic guide →House lost power during a grid outage despite a charged Sunsynk battery. EPS (Emergency Power Supply) mode must be correctly wired and enabled in settings. Also covers EPS SoC reserve threshold and load circuit configuration.
See diagnostic guide →Solarman, WiFi & datalogger faults
The inverter keeps running when Solarman goes offline — only remote monitoring is lost. Usually a datalogger WiFi issue after a router change or broadband switch.
Solarman (formerly PVMaster) shows no data or last updated hours ago. The inverter is still operating — only monitoring is affected. Router changes, password updates, and logger hardware failure are the most common causes.
See diagnostic guide →Sunsynk dataloggers require 2.4GHz WiFi. Many monitoring failures after a router upgrade are caused by the new router defaulting to 5GHz or using band steering. We reconfigure the datalogger remotely from your Solarman access details.
See diagnostic guide →Sunsynk fault code index
Sunsynk fault codes appear in the Solarman app and on the inverter display. Common code groups cover grid voltage faults (E02X series), battery communication errors, DC bus faults, and temperature protection trips. Share your exact code when you book — we identify the root cause as part of the remote diagnostic.
How we approach Sunsynk fault diagnosis
Every fault guide above is built from real Sunsynk diagnostic sessions. The pattern we see most often is a homeowner who has set up their charge schedule correctly — the windows look right in Solarman — but the battery still isn't charging at the cheap rate. The root cause is almost always one of three things: the grid charge enable toggle, an SoC minimum threshold that's too high, or a BST/GMT offset after the clocks changed. None of these require a site visit.
Sunsynk's Solarman monitoring platform gives us a detailed view of charge/discharge history, TOU schedule logs, DC input voltage, and fault code registers. That's why most Sunsynk problems — including grid disconnection faults and monitoring issues — can be fully diagnosed and resolved remotely, often in a single session.
If your fault isn't listed above, or you've worked through a guide and the problem persists, book a remote diagnostic. We're independent from Sunsynk Energy and your installer — you get an objective second opinion on what's actually wrong and what needs doing.
Sunsynk problems — common questions
Can't find your fault, or the guide didn't fix it?
A remote diagnostic session finds the exact cause using your Solarman data, error history, and TOU schedule — then gives you a clear repair plan. Most Sunsynk problems are resolved in a single session.
- Independent — not affiliated with Sunsynk Energy
- Emergency repair available
- Remote diagnosis before any site visit
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Got a solar fault or need a quick answer? Drop us a message — we usually reply within a few minutes. Mon–Fri, 9am–7pm.