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Solar Repair & Support in Cardiff

Cardiff is home base for our engineer — the one place on this site where you get a genuinely locally based independent solar engineer, not a visit booked in from far away. We cover the whole Welsh capital, from the Victorian terraces of Cathays, Roath and Canton to the newer estates at Pontprennau and Pentwyn, plus Penarth, Barry, Dinas Powys and Caerphilly. Same-day to next-day on-site for urgent faults; free remote diagnostic same-day.
from £245 · free remote diagnostic first · no call-out fee
  • On-site repair from £245
  • Inverter replacement £795
  • Free remote diagnostic — same-day written report
Cardiff solar engineer

Tell us what's happening with your system. We'll confirm whether it needs a remote diagnostic or an on-site visit, and give you a clear price before any work starts. Because we're based in Cardiff, urgent faults across the city and the Vale are usually same-day to next-day.

Book a visitFree remote diagnostic · no fix, no fee

Independent — not affiliated with any installer or manufacturer.

Absolutely wonderful support. I have a GivEnergy system that was installed in 2022, and a firmware update was flagged in the app, so I proceeded to update the software .... and immediately regretted it, as my inverter came up with an error, and was not working at all! With no GivEnergy support available, and my installer saying there was nothing he could do, I googled help, and found Ron. What a stroke of good luck! Submitted an on line enquiry late morning, and received phone call just after 5 pm, and later that evening Ron was able to supply me with old firmware no longer available on the GivEnergy web site. I was then able to update the firmware using a GivEnergy youtube video as reference, and hey presto the system was back up and running. One further slight adjustment by Ron and we are back normal. What a relief. I have no hesitation in recommending Solar Tech Support if you have a problem. Great service! And if you are a GivEnergy system owner, whatever you do, DO NOT UPDATE FIRMWARE!

Neill Ginn · Jul 2026 Google

Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.

Hugh Speirs · Apr 2026

When my GivEnergy battery started playing up it became basically useless and several companies I called said they couldn’t help. Solar Tech Support really knew their stuff, communicated very well and resolved the problem quickly. Without them I’d have had to buy a replacement battery.

A D · Jun 2026 Google

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.

Julian F · Jun 2026 Google

Ron made more sense in 20 mins than our installer has done over the last 12 months There is a jungle out there and you need someone like Ron to give a comprehensive overview and solution

David · May 2026

Ron was extremely helpful and tried his best to repair/reset our GivEnergy inverter remotely. In the event he was unsuccessful but he couldn’t have been more helpful. If you have problems with a GivEnergy system please contact him. Highly recommended

Neil Crichton · Jun 2026 Google
Local Knowledge

Solar in Cardiff — a locally based engineer, not a distant call-out

Cardiff is where our engineer is based — so unlike most of our coverage, repair work here is genuinely local. The Welsh capital has a distinctive solar profile: a huge stock of compact arrays on Victorian and Edwardian terraces, a wave of council and Welsh Government scheme installs from the early 2010s, and the salt-laden air of the Severn Estuary working on the wiring near the bay and Penarth. We know the hardware, the fault patterns, and the roads — and we can usually be there same-day to next-day.

Victorian terraces with compact arrays

Cathays, Roath, Canton, Grangetown, Splott and Adamsdown are dense streets of Victorian and Edwardian terraces, many with bay-fronted roofs carrying compact 2–4kW systems. Narrow south-facing pitches, chimney shading, and limited roof area are the norm. These typically run Fronius, Solis or Growatt string inverters with 8–12 panels — simple, but the inverters are now well over a decade old and approaching end of life.

Council and scheme FiT-era installs

Cardiff took up domestic solar early in the feed-in tariff years. Alongside private installs, council housing schemes and Welsh Government energy programmes such as Arbed and Nest brought solar and other measures to homes across the city and the wider Valleys. Many of these households were left with little documentation and no monitoring setup — so when something goes wrong, owners often don't know what brand they have or who to call.

Severn Estuary salt-air exposure

Cardiff Bay, Penarth, Grangetown and the waterfront districts sit on the Severn Estuary, an exposed tidal coastline where salt-laden air carries inland off the water. That coastal air accelerates corrosion in roof-level MC4 connectors, DC isolators and junction boxes faster than at inland sites. The panels cope fine; it's the electrical fittings and switchgear that degrade, so these systems benefit from more regular checks.

Battery retrofits on older systems

More Cardiff homeowners with existing FiT-era arrays are adding storage — most often GivEnergy, with some Sunsynk and Fox ESS. Retrofitting a battery onto a system that was never designed for one creates integration work: CT clamp placement, hybrid inverter compatibility, charge scheduling and tariff optimisation all have to be configured correctly. We see plenty where the battery is fitted but was never properly set up, so it isn't actually saving money.

Services

What we do in Cardiff

Cardiff's mix of compact terraces, suburban estates and coastal waterfront properties produces a wide range of system types and faults. Being locally based means we remote-diagnose before every visit and then attend quickly. No call-out fees. All pricing confirmed in writing.

Common Problems

What goes wrong with solar systems in Cardiff

Cardiff's install base is dominated by FiT-era systems from the early 2010s, layered with newer battery retrofits and shaped by the city's coastal estuary climate. These are the faults we see most across the capital.

1
Ageing FiT-era string inverters reaching end of life

Most domestic systems across Cardiff went in during the feed-in tariff boom of 2011 to 2016. They typically run Fronius IG, Solis, or Growatt string inverters — all now past the 10-year mark and the first major component to fail. Symptoms: blank display, no generation, intermittent fault codes, or tripping the consumer unit. The panels are almost always fine. Replacing the inverter with a modern hybrid unit restores full output and makes the system battery-ready. Inverter replacement →

2
DC isolator failures — worst near the bay and the coast

DC isolators are the weakest point in any solar installation, and salt-laden estuary air makes them fail faster. Systems around Cardiff Bay, Grangetown, Penarth and the waterfront see accelerated corrosion in isolators, MC4 connectors and junction boxes. A failed DC isolator can trip the whole system or, at worst, present a fire risk. We replace these during repair and maintenance visits and carry stock of the common types. Fault diagnosis →

3
Orphaned systems with no documentation or support

Cardiff's council and government-scheme roll-outs left thousands of homes with solar but little paperwork — no MCS certificate to hand, locked or never-activated monitoring accounts, and no warranty route once the original installer moved on or closed. The systems usually still generate; they just have no one managing them. We handle full recovery: monitoring transfer, documentation rebuild, warranty verification, and ongoing maintenance. Installer gone bust guide →

4
GivEnergy battery retrofit not configured properly

Homeowners adding a GivEnergy battery to an existing FiT-era system across Cardiff often find it isn't saving them money. The system charges during the day but imports from the grid through the peak evening hours instead of discharging the battery. The cause is almost always configuration: CT clamp direction or placement, eco mode settings, charge schedule timing, or a firmware update that has reset values. We diagnose and fix this remotely in most cases. GivEnergy support →

Installer gone bust?

Your Cardiff installer has closed — we take over from here

A great many of the companies that fitted solar across South Wales during the FiT boom are no longer trading — the Cardiff installer PV Solar Solutions was dissolved back in 2015, for example. If the firm that installed your system has gone into liquidation or simply stopped answering, you are not stuck — and you don't need to find the original installer to get help. The recovery process is the same regardless of who fitted it: monitoring transfer, documentation rebuild, warranty verification, and fault diagnosis. We pick it up from wherever it was left.

It doesn't matter who installed your system — the recovery process is identical. Full installer gone bust guide or book a call.

Brands

GivEnergy, Fronius, Solis — we fix them all in Cardiff

GivEnergy is the brand we're called to most across Cardiff — it dominates the city's battery retrofits, and most issues are configuration rather than faulty hardware. Alongside it, the older FiT-era arrays still run Fronius and Solis string inverters. Each brand has its own diagnostic methods, firmware management and warranty process, and we know them all.

GivEnergy — battery diagnostics, CT clamp & eco-mode setup, charge schedules, firmware, warranty claims
Fronius — inverter replacement, error code diagnosis, end-of-life swap
Solis — string inverter faults, monitoring setup, firmware updates
Growatt, Sunsynk, SolarEdge, Fox ESS, Huawei — all supported
19+ brands — independent, no manufacturer bias
Local Coverage

Areas of Cardiff we cover

From our Cardiff base we cover the whole city and out into the Vale of Glamorgan and Caerphilly. Because we're locally based, there's no long-distance lead time — same-day to next-day on most urgent faults.

Cardiff Bay
Cathays
Roath
Canton
Pontcanna
Llanishen
Cyncoed
Whitchurch
Rhiwbina
Llandaff
Grangetown
Penylan
Radyr
Pentwyn
Penarth
Barry

Also covering Splott, Adamsdown, Heath, Pontprennau, Dinas Powys and Caerphilly. Not listed? If you're in Cardiff or the surrounding South Wales area, we almost certainly cover you — get in touch and we'll confirm. See all the areas we cover.

New homeowner

Just bought a house in Cardiff with solar panels?

Cardiff has thousands of homes that took up solar during the feed-in tariff years, and a great many change hands with little or no paperwork. The new owner typically gets no documentation, no monitoring access, and no explanation of the FiT payments, inverter brand, or warranty status. We visit — usually within days, because we're local — identify every component, check performance, set up monitoring in your name, and hand over a written report covering everything.

System identification — panels, inverter, battery, wiring
Monitoring transfer into your name
MCS certificate and warranty status check
FiT registration verification and transfer guidance
Written condition report and recommendations
FAQ

Solar repair in Cardiff — common questions

Cardiff is where our engineer is based, so lead times here are the shortest on the whole site. For urgent faults like a dead inverter or total generation loss, we can usually attend same-day to next-day across the city and the surrounding Vale of Glamorgan. Scheduled work such as inverter replacements and annual maintenance is normally within the same week. A free remote diagnostic can often identify the fault same-day before we even arrive.
Yes. From our Cardiff base we cover the whole city — Cathays, Roath, Canton, Pontcanna, Llanishen, Cyncoed, Whitchurch, Rhiwbina, Llandaff, Grangetown, Splott, Penylan, Radyr, Pentwyn and Pontprennau — plus the Vale of Glamorgan towns of Penarth, Barry and Dinas Powys, and Caerphilly to the north. All at the same pricing. Because we are locally based, there is no long-distance lead time on any of these.
Inverter replacement starts £795, which includes the new unit, removal of the old one, installation, configuration, and commissioning. The exact price depends on the brand, model, and system size. Many Cardiff systems still run original FiT-era string inverters from 2011 to 2016 that are now past the 10-year mark — a free remote diagnostic confirms exactly what is needed before we quote. Inverter replacement service →
Usually yes, and often remotely. When a GivEnergy battery charges in the day but the house still imports from the grid in the evening, the cause is almost always configuration rather than faulty hardware — CT clamp position or direction, eco mode, or the charge schedule not matching your tariff. We diagnose it on your GivEnergy portal, correct the settings, and confirm the battery is discharging when it should. A free remote diagnostic comes first; we only charge if we fix it.

Solar panels not working in Cardiff? Tell us what's happening.

Describe the fault — what you're seeing (or not seeing), the brand if you know it, when it started. We'll come back with a clear plan and price, usually same day. Cardiff is our home base, so on-site visits are typically same-day to next-day.

  • On-site repair from £245 · inverter replacement £795
  • Solar panel maintenance from £195
  • Free remote diagnostic — same-day written report

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Call 07944 877 329 Book free diagnostic