Your solar system diagnosed,
recovered and back online.
When your inverter faults, battery stops charging, or monitoring goes dark — you need engineering clarity, not sales. STS provides independent, evidence-led solar diagnostics and repair across the UK.
Most solar faults are diagnosed remotely in a single session. Tell us what you're seeing and we'll work it out.
Book a Remote Diagnostic — from £75 → See the Solar Health PlanSafety: do not open inverter or battery enclosures. If you smell burning or see arcing, isolate at the consumer unit and call 999.
Brands we support
Not a call centre. Not an electrician. The specialist.
STS was founded by an electronic engineer from the University of York who spent three years as Technical Director at one of the UK's largest renewable energy companies — overseeing around 1,000 solar installations a year at peak. That means every major inverter brand, every battery system, every failure mode — diagnosed from the inside.
Most people who call a solar problem number reach a call centre that logs a ticket and dispatches an electrician. STS is different: you get engineer-level diagnosis from someone who has seen your exact fault hundreds of times.
Start remote. Fix fast.
We diagnose the real issue first, then do the minimum required work to restore safe generation. Remote-first, on-site only when needed.
Remote Solar Diagnostic
Fault codes, underperformance, battery issues, monitoring outages. We review your evidence and identify the real cause.
System Recovery
Installer gone bust, access locked, ownership transfer, monitoring rebuild. We restore control of your system.
On-Site Technical Visit
Hardware faults, CT rewires, EPS circuit checks, independent inspections. Targeted visits, no guesswork.
Solar Health Check
Full system performance audit. Catch underperformance before it costs you — ideal after purchase or installer change.
Book health check →Independent Inspection
MCS compliance checks, post-install snag inspections, warranty claim support. Unbiased, documented, defensible.
Book inspection →Solar Health Plan
Annual cover for diagnostics, priority support and performance monitoring. Peace of mind, year-round.
See health plans →Recognise your fault?
Every fault below has a repeatable diagnostic path. Click your symptom to go straight to the right page.
Hard stops, no output, complete shutdown, fault state.
Charge windows, CT errors, BMS faults, firmware issues.
App not updating, portal dark, logger disconnected.
Inverter tripping high voltage, evidence packs, DNO.
Inverted readings, backwards battery behaviour, wrong data.
Wrong cap, meter conflicts, DNO compliance failures.
Access locked, no warranty support, orphaned system.
Generation lower than expected — shading, config, hardware.
Look up your inverter error code by brand — SolarEdge, Huawei, GivEnergy, Growatt and more.
Get more from what you already have.
Add battery storage, install EPS backup power, expand an existing battery stack, replace a failing inverter, or protect your panels from birds. Every upgrade is scoped, priced and handled by STS.
No battery yet? Add a GivEnergy or Sunsynk hybrid inverter and battery to your existing solar array.
See battery upgrade guide →Already have a hybrid inverter? Add a second or third battery to store more solar and import cheaper overnight energy.
See storage expansion guide →Power critical circuits during a grid outage. GivEnergy and Sunsynk EPS installation — from configuration to dedicated backup circuit.
See EPS installation guide →Aging, faulty or end-of-life inverter? Replace like-for-like or upgrade to a hybrid model. All brands, UK-wide.
See inverter replacement guide →Just bought a house with solar?
Don't know what you have, who installed it, or if it's even working correctly? We identify the system, transfer your monitoring access, and get you fully in control.
Start here →Your installer has gone bust?
No response, company dissolved, or left with a locked system? We recover monitoring access, rebuild documentation, and support warranty claims — without depending on the original installer.
Get recovery support →Managing a commercial PV system?
Independent operations and maintenance for commercial solar — no manufacturer ties, no installer partnerships. Annual O&M contracts, emergency fault response, system takeover, and one-off performance audits. All brands, UK-wide.
Annual inspection, real-time monitoring, priority engineer response, and performance reporting.
Same-day remote triage, next-business-day on-site. Inverter failure, generation loss, safety alarms.
Transition from a previous provider. Baseline audit, documentation recovery, structured handover.
One-off performance assessment. Due diligence, insurance, disputes, pre-warranty expiry. No contract required.
Deep brand expertise
Each brand page covers brand-specific fault codes, configuration guides, common problems and repair services.
Yorkshire-based. UK-wide remote.
Remote diagnostics available nationwide from day one. On-site visits cover Yorkshire and surrounding regions. We're expanding — check your area.
Transparent pricing.
No call-out surprises. Remote-first means lower cost. We tell you what's needed before you commit to a visit.
Evidence review + structured diagnosis + written action plan.
Full system performance audit. Catch issues before they become faults — ideal after purchase or installer change.
Targeted physical checks. CT rewires, isolation faults, EPS, hardware.
Remote-first: if the fastest, safest route is remote, we take it. On-site only confirmed necessary before booking.
Solar knowledge base
Practical guides written by engineers — not marketing copy.
What to check before, during and after installation — fully referenced to MIS 3002:2025, MIS 3012:2025 and BS 7671:2018+A3:2024. Don't make final payment without it.
Read the guide + download PDF →DNO notification vs approval, export limits, Fast Track G99, and what happens when paperwork is missing.
What they do, how direction affects readings, and how to spot a miswire.
BMS, SoC, charge rates, and why your battery behaves the way it does.
SEG registration, eligible suppliers, MCS requirements, and how to get paid for your export.
EPS circuits, island mode, switchover time, and what actually runs during a power cut.
Common questions
Yes — most faults are diagnosed and resolved remotely. We start with monitoring data, settings review and evidence-led troubleshooting. If an on-site visit is required, we confirm exactly what needs checking so there's no wasted callout.
We specialise in this. We handle monitoring access transfer, rebuild missing documentation, support MCS certificate queries, and compile warranty evidence packs — so you're no longer dependent on an installer that no longer exists. See installer gone bust support →
Common causes include incorrect charge window settings, CT clamp direction errors, BMS communication faults, firmware mismatches, or export limit conflicts. We diagnose the exact cause and apply the correct fix. See battery not charging support →
No. We never ask homeowners to open covers or perform live electrical work. We focus on evidence, monitoring data, safe external checks, and clear guidance. If physical work is needed, a qualified engineer visits on-site.
This is more common than you'd think. We identify the system, assess performance against design spec, check MCS documentation, and get you proper monitoring access. See inherited system support →
All major UK brands: SolarEdge, Huawei, Sunsynk, GivEnergy, Growatt, Solis, Enphase, Fronius, Fox ESS, Tesla Powerwall, Pylontech, Sofar, SolaX, Hanchu, Lux, Dyness, AlphaESS, Duracell Energy, and Sigenergy. Browse all brand pages →
Ready to get your system working properly?
Tell us what's happening. We'll review your details and come back with a clear diagnosis path and a proposed time to talk.