Solar panel repairs in the UK are often harder to arrange than the installation was, because many installation firms do not take on small repair jobs. The panels themselves are rarely the problem. What fails is the equipment around them: isolators, connectors, inverters and optimisers. This guide covers what actually breaks, what you can safely check yourself, who to call, and which warranty route pays.
If your system is producing less than you expect but nothing is obviously broken, start with my low output diagnostic guide instead. This page is for the point where you know something has failed and need it fixed.
What actually goes wrong with solar panel systems?
The faults that interrupt generation are usually electronic: the inverter, individual optimisers or microinverters, and the monitoring hardware. The faults that create safety risk are usually connections: DC isolators and the plug-in connectors between panels. The safety half of that picture is well documented. The BRE National Solar Centre investigated around 80 potential PV fire incidents for the UK government and traced roughly 30 percent of them to DC isolator faults, with connectors the next most common origin (BRE, Fires and Solar PV Systems).
The same research found poor installation behind about 36 percent of the incidents where a root cause could be identified. Water getting into an isolator through an upward-facing cable gland, a connector crimped badly, or two incompatible connector brands mated together are all installation faults that sit dormant for years before they announce themselves.
Away from the fire statistics, there is no official league table of everyday faults, but the pattern among owners is consistent. Inverters are working electronics with a finite life, and an inverter fault is the failure most owners eventually meet. Individual power optimisers can die and quietly take one panel out of production for months if nobody watches the monitoring. Birds nesting under arrays chew cables and pack the gap with debris, a problem I cover separately in my bird proofing guide. Cracked glass does happen, but the panels themselves are generally the most reliable part of the system, and they were the fire origin in only a handful of the BRE incidents.
What can you safely check yourself?
You can safely check the monitoring app, the inverter display and error codes, the AC isolator and consumer unit breaker, and the array visually from the ground. You cannot safely open anything on the DC side, because solar panels cannot be switched off in daylight.
That last point deserves emphasis. The official UK installation guidance is blunt about it: a PV system’s DC terminals remain live at all times during daylight hours, which is why installations carry labels reading “live during daylight” (DTI/BRE installation guide). The same guidance warns never to unplug the panel connectors under load, and BRE’s fire investigations explain why: unlike mains AC, a DC arc does not extinguish itself once struck. Turning off the AC isolator stops export, but every DC cable between the panels and the DC isolator stays live while the sun is up.
So the useful homeowner checklist is deliberately boring: note the inverter error code and look it up before anyone visits, since codes often identify the fault precisely. My Solis OV-G-V01 write-up is an example where the code points at the grid rather than the equipment. Photograph anything visible from the ground, check whether one string or the whole system is down in the app, and gather the paperwork: the commissioning certificate, panel and inverter model numbers, and any warranty documents. A repair visit with that information ready is a shorter, cheaper visit.
Who repairs solar panels in the UK?
Any competent electrician can legally work on a solar system. MCS certification is a scheme for certifying new installations, mainly so they qualify for export payments, and there is no rule that repairs must be done by an MCS installer.
That surprises people, because MCS branding is everywhere in solar. But MCS matters when a system is first installed and certified for the Smart Export Guarantee. Repairing an existing system sits under ordinary electrical rules instead: the work must be safe and meet BS 7671. In England, Part P of the Building Regulations makes most repair and maintenance work non-notifiable unless it involves a new circuit, a consumer unit change or work in a special location such as a bathroom (Approved Document P); Scotland runs its own building standards system, so check locally there.
In practice you want an electrician who knows PV, because the DC side, string voltages and daylight-live working are outside a general domestic electrician’s daily routine. The harder problem is willingness rather than legality. Repair visits are small jobs with awkward access, and many installation firms simply do not take them. Firms that advertise servicing and repairs as a distinct service exist in most regions; expect to phone several. If the fault is on the roof, factor in access from the start, because scaffolding can cost more than the repair itself.
Can you replace a single broken solar panel?
Usually yes, but rarely with an identical panel. Models are discontinued within a few years, and the replacement has to be electrically compatible with the rest of its string.
Panels wired in series behave like a chain: the string’s current is set by its weakest module. A replacement with meaningfully different current characteristics drags the whole string toward its own performance, so the goal is a panel with closely matched electrical specs, not just similar wattage. Physical size matters too, since the new panel has to land on the existing rails, and connector compatibility is a genuine safety point rather than a fussy detail, because mismatched connector brands are one of the documented fire causes in the BRE research.
The realistic options are a close-spec current panel, a matching used panel from the secondary market, or, on systems with optimisers or microinverters, a much wider choice of modern panels, since per-panel electronics relax the string matching problem, subject to size, connector type and the electronics’ own compatibility limits. If one panel on a plain string system has failed and a match is hard to find, an installer can sometimes rewire around it and leave a smaller string running until a fuller refit makes sense.
What happens when the inverter fails?
Inverter failure is the most common serious fault, and the fix is normally replacement rather than repair. One step people miss: your DNO must be informed when the inverter is replaced, even like for like.
Board-level inverter repair barely exists as a consumer service in the UK, so a failed unit past its warranty generally means a new inverter. If the replacement has the same capacity, this is straightforward, but the Energy Networks Association’s connection guides list informing your network operator about a replaced generating unit among the standing obligations of a connected system (ENA G98 guide). It is a notification, not a new application. Going up in capacity is different territory, which I cover in my G98 to G99 guide.
Warranty terms vary more for inverters than for panels. Five years standard is still common, with paid extensions available, while some manufacturers offer 10 or 12 years and microinverter makers up to 25. Check whether your unit’s full term required registration after installation, because several brands run shorter default cover if nobody registered the serial number. Current models and their warranty terms are in my inverter directory.
What do solar panel repairs cost?
Budget for three separate lines: a diagnostic visit at normal electrician rates, the replacement hardware, and access. Access is the line that surprises people, because scaffolding for roof work often costs more than the part being replaced.
There is no reliable national price list for solar repairs, and I distrust the neat cost tables that circulate on lead generation sites. What I can anchor is the access line: my scaffolding cost guide covers what a domestic scaffold realistically costs and what pushes the price up. Ground-level work such as an inverter swap avoids that cost entirely, which is one reason inverter faults, though more common, are often cheaper to resolve than a single cracked panel on a two-storey roof. For context on full-array labour, my removal and reinstallation cost guide covers the day-rate reality of getting people onto a roof legally and insured.
Which warranty covers which repair?
Solar systems carry several overlapping promises: the manufacturer’s product warranty, the panel performance warranty, the installer’s workmanship guarantee, sometimes an insurance-backed guarantee behind that, and your statutory consumer rights underneath everything. Matching the fault to the right layer decides whether the repair costs you anything.
Broadly: a component that failed on its own is a manufacturer product warranty claim, routed through the installer or distributor. A fault traceable to how the system was fitted, such as the classic leaking isolator gland, belongs to the installer’s workmanship guarantee, which RECC members must provide for at least two years and back with insurance in case they stop trading (RECC Consumer Code). If the installer has gone, an insurance-backed guarantee steps in for workmanship faults, though the insured term can be shorter than the paper guarantee. Beneath all of it sits the Consumer Rights Act 2015, which requires goods to be of satisfactory quality and durable, and services to be performed with reasonable care and skill.
The fine print matters enough that I have written a separate guide to what solar warranties actually cover, including the exclusions and who pays for testing and labour on a performance claim. Read it before assuming a 25-year warranty means 25 years of free repairs. It does not.
How do you avoid being stranded with an orphaned system?
The hardest repair situation is the one where the company behind your equipment no longer exists. The clearest recent example is GivEnergy Ltd, which entered administration in April 2026; the administrator has stated the company ceased trading and that no further hardware warranties will be honoured by GivEnergy Ltd. For owners of its equipment, the manufacturer route for those warranties is closed, though installer guarantees, the seller and statutory consumer rights remain separate routes.
You cannot fully insure against that, but you can tilt the odds. Keep the full documentation pack from day one, because a future repairer, buyer or insurer will ask for it, and my solar documents guide lists what belongs in it. Prefer equipment that is widespread and standard rather than clever and proprietary, since common hardware keeps a repair market even after its maker disappears. Check whether an insurance-backed guarantee actually exists for your installation rather than assuming it does. And watch the monitoring occasionally: a dead optimiser noticed in a week costs one visit, while the same fault noticed at the annual bill costs a season of lost generation.
None of this needs to be learned in a crisis. An hour spent now filing the paperwork, photographing the serial numbers and setting a monthly reminder to glance at the monitoring will make the eventual repair visit shorter, cheaper and far less dependent on whoever happens to answer the phone.
