Solar Panel Repairs: Common Faults, Costs & Who Pays
Panels down, inverter flashing red, or a mystery drop in generation? Here’s what repairs really cost in 2026, what’s covered by warranty or insurance — and when repair is the wrong answer.
The short answer
Most solar repairs are cheaper than owners fear: callout and diagnosis from ~£150, wiring or connector fixes from £100, a damaged panel replaced for £250–£450, and an inverter — the most common failure by far — replaced for £500–£1,500. Scaffolding, where needed, adds £300–£800.
Two rules save owners the most money: check who should pay first (warranty for defects, buildings insurance for storm and impact damage — not your wallet by default), and on systems past 12–15 years, compare repair against replacement before sinking money into ageing kit.
What this guide covers
Solar systems are genuinely low-maintenance — no moving parts, panels warrantied for 25+ years — but “low-maintenance” isn’t “no-maintenance”. Inverters wear out, connectors corrode, storms happen, and pigeons treat cable runs as chew toys. When something does go wrong, the repair market is small, quotes vary wildly, and plenty of owners get talked into replacing things that a £100 fix would have sorted — or, just as costly, keep patching a system that should be retired.
This guide gives you the 2026 numbers and the decision logic. It’s written for owners, but if you’re researching solar and worried about upkeep, it doubles as an honest look at what ownership actually involves — spoiler: budget a little for one inverter replacement over 25 years and you’ve covered the likely big one.
Solar repair costs at a glance (2026)
| Repair | Typical cost | Notes |
|---|---|---|
| Callout & diagnosis | from £150 | Often credited against the repair if you proceed |
| Wiring / connector repair | £100–£300 | Corroded MC4s, chewed cables, loose DC connections |
| Replace one damaged panel | £250–£450 installed | Complex or discontinued panels can run to £700 |
| Inverter repair | £150–£500 | Fans, boards, firmware — where economic |
| Inverter replacement | £500–£1,500 | The most common major repair on UK systems |
| Scaffolding (if roof access needed) | £300–£800 | The silent budget-killer on small roof jobs |
| Annual service / health check | £100–£200 | Optional but catches faults early |
The scaffolding line deserves attention: it’s why a £300 panel swap can arrive as an £900 quote. Some firms use roof ladders or towers for single-panel jobs; it’s always worth asking how they’ll access the roof, because it can halve the bill. And if several jobs need doing — a panel swap plus bird-proofing plus a clean — bundling them under one scaffold hire is far cheaper than three separate visits.
The 7 most common solar faults
- 1. Inverter failure or fault codes — the number one cause of dead systems, covered in its own section below.
- 2. Tripped breaker / RCD — after a power cut or electrical storm, the solar supply breaker can trip and stay off unnoticed for months. Free to check, free to reset.
- 3. Monitoring dropout — the WiFi dongle loses your router and the app shows nothing, while the system generates happily. No engineer needed; re-pair the dongle.
- 4. Connector and wiring degradation — MC4 connectors corrode, junction-box seals fail, and rodent or pigeon damage exposes cables. Causes gradual output drops or intermittent cut-outs. £100–£300 to put right, but genuinely urgent when DC cables are exposed — arcing DC is a fire risk.
- 5. Physical panel damage — cracked glass from impact, hail or a dropped tool. Here’s the truth most repair firms will tell you and some won’t: panels are not field-repairable. Cracked glass, cell damage, hotspots and delamination all mean replacement. One panel can be swapped individually — the rest of the array stays.
- 6. Hotspots and delamination — browning, bubbling or burn marks on a panel, usually a manufacturing defect showing up over time. This is warranty territory: performance warranties on decent panels run 25+ years, which is one reason panel brand choice matters at purchase (see our best solar panels guide).
- 7. Bird damage and nesting — pigeons under panels chew cables, block ventilation and coat everything in droppings. The fix is proofing plus any cable repairs, and it’s worth doing promptly — nests under arrays are a genuine fire-and-damp risk.
Inverter failures: the big one
If your system has stopped generating entirely, the inverter is the prime suspect. It’s the hardest-working electronics in the setup and typically lasts 10–15 years against the panels’ 25–30 — meaning almost every solar system will need one inverter replacement in its lifetime. At £500–£1,500 installed, it’s the repair to plan for rather than be surprised by.
Before paying, though, check three things. First, the fault code — many are grid-side (over-voltage shutdowns on sunny afternoons are usually your street’s grid running high, not your hardware; your installer can report it to the network operator). Second, the warranty — inverter warranties run 5–12 years depending on brand, and some extend free on registration; if you own a Solis, for example, registration doubles cover from 5 to 10 years, a catch we cover in our Solis review. Third, the upgrade question — if you’re paying for a new inverter anyway and have ever wanted battery storage, a hybrid inverter costs only a little more and makes your system battery-ready; our inverters guide and battery guide cover that fork in the road.
The FIT-era warning
If your system went in between 2010 and 2015 under the old Feed-in Tariff, be careful before replacing panels or making major changes — altering a FIT-registered system can affect your payments, which are often worth more than the repair. Like-for-like inverter replacement is fine; changing capacity may need notifying your FIT licensee first. Ask your repairer to confirm in writing that the work won’t affect FIT eligibility.
Who pays: warranty, insurance, or you?
| Cause | Who usually pays | Watch out for |
|---|---|---|
| Manufacturing defect, premature failure, delamination | Panel / inverter warranty | Warranty may need proof of registration & service history |
| Storm, impact, fire, theft, vandalism | Home buildings insurance | Panels must be declared on your policy |
| Installation faults (leaks, loose mounts, bad wiring) | Installer’s workmanship warranty | Typically 2–10 years; MCS installers must offer one |
| Wear-and-tear, accidental DIY damage | You | Excluded from almost everything |
The practical order of operations when something breaks: photograph everything from the ground, check your paperwork for warranty terms, and call your insurer before commissioning repairs if the cause is storm or impact — insurers can refuse claims for work done without approval. And a five-minute job today that prevents a claim tomorrow: ring your home insurer and confirm your panels are declared. Undeclared panels are one of the most common reasons solar claims fail.
What’s safe to DIY (honestly: very little)
Here’s the safety fact that surprises most owners: solar panels produce live DC voltage whenever daylight hits them — even with the inverter switched off. There is no off switch for the sun. DC doesn’t behave like household AC either: it arcs, and it holds. Combine that with roof-height working and the DIY boundary is simple:
- Safe: visual checks from the ground (binoculars are your friend), reading inverter fault codes, resetting a tripped breaker, re-pairing a WiFi dongle, monitoring output in the app.
- Not safe: anything involving the panels, DC cabling, connectors, or the roof. If a panel is visibly damaged, keep people away and don’t touch it — cracked panels can still be live.
- Also worth knowing: dead panels are WEEE-regulated waste — they can’t go in a skip. A proper repair firm disposes of them; a cowboy leaves them in your garden.
Finding a solar repair company near you
The repair market is thinner than the install market — many installers only want new-build jobs — so here’s what actually works:
- Start with your original installer if they’re still trading; they know the system and their workmanship warranty may apply.
- Look for MCS-certified firms — certification is for installations, but MCS firms working on your system protects future warranty and export-tariff standing, and it filters out the van-and-a-ladder outfits.
- Ask the right questions: is diagnosis credited against the repair? How will you access the roof (scaffold vs tower — big cost difference)? Are replacement parts new and warrantied? Will the work affect my FIT payments or panel warranty?
- Get two quotes for anything over ~£500 — with inverter replacements especially, prices for identical hardware vary by hundreds of pounds.
Repair or replace? The honest maths
✓ Repair makes sense when…
- The system is under ~12 years old
- It’s a single identifiable fault (inverter, one panel, cable)
- Warranty or insurance is footing the bill
- You’re on FIT payments worth protecting
- Repair total is well under half of replacement cost
✗ Replacement wins when…
- The system is 15+ years old and faults are stacking
- It’s a tiny old array (1–2kW) on a roof that could hold 4kW+
- Panels are discontinued and matches are unobtainable
- A repair bill approaches 50% of a new system’s price
- You want a battery and the old kit can’t support one
The context that changes this decision in 2026: modern panels generate far more per square metre than 2012-era kit, full systems are cheaper than they’ve ever been — a 4kW system runs £5,000–£7,500 installed with 0% VAT until March 2027 — and new systems restart the warranty clock for 25 years. An ageing 2kW array limping along on its second inverter is very often worth more to you as a skip-load than as a patient.
Frequently asked questions
How much do solar panel repairs cost in the UK?
Callout and diagnosis from around £150, wiring or connector repairs from £100, a damaged panel replaced for £250–£450 installed, and inverter replacement at £500–£1,500. Scaffolding, where needed, adds £300–£800 — always ask how the firm plans to access the roof.
Can a cracked solar panel be repaired?
No — not meaningfully. Cracked glass, cell damage, hotspots and delamination all mean replacement. Panels are sealed units and aren’t field-repairable. The good news: one panel can be swapped without touching the rest of the array.
Who pays — warranty or insurance?
Defects and premature failure fall under the panel or inverter warranty; storm, impact, fire and theft usually fall under home buildings insurance if your panels are declared on the policy; installation faults fall under the installer’s workmanship warranty. Wear-and-tear is on you — which is what the repair costs above are for.
Why have my solar panels stopped working?
Check the cheap causes first: a tripped breaker, a WiFi dongle that’s dropped offline (system fine, app blind), then the inverter fault code. The inverter is the most common genuine failure — it typically lasts 10–15 years against the panels’ 25–30. Our inverters guide explains what it does and why it fails first.
Is it safe to repair solar panels myself?
No. Panels produce live DC voltage whenever there’s daylight — even with the inverter off — and DC arcs are a serious shock and fire risk, before you add roof-height working. Ground-level checks and resetting a breaker are the DIY limit.
Should I repair or replace an old system?
Rule of thumb: on a system over 12–15 years old, if the repair bill approaches half the cost of a new system, replace. Modern systems generate more, cost less than ever, carry fresh 25-year warranties and can be specced battery-ready — compare quotes before paying for another patch.
Repairs are rarer — and cheaper — than owners fear
The bottom line: Most faults are minor, the big one (the inverter) is predictable and budgetable, and warranty or insurance covers more than owners realise. The one repair mistake that really costs money is pouring cash into a system that’s earned its retirement.
Get my free quotes →The verdict
Solar repairs follow a pattern: cheap causes first (breakers, WiFi, connectors), one predictable big-ticket item (the inverter, once per system lifetime), and a payer other than you for defects and storm damage — if your panels are declared and your warranties registered. Check those two things this week and you’ve done the best free maintenance available.
And when a repair quote on an ageing system makes you wince, get a replacement quote alongside it. Sometimes the honest answer — the one a repair firm won’t volunteer — is that your roof deserves better than another patch.
Important
Going Solar UK is an introduction service, not an installer or repair firm. We don’t diagnose, repair, or fit solar systems ourselves. Costs in this guide are indicative 2026 market averages and vary by region, system and fault — always get a professional diagnosis and quotes before proceeding. Nothing here is electrical-safety training: treat all solar DC wiring as live and leave it to qualified engineers. Insurance and warranty outcomes depend on your specific policy and terms.
We may receive a commission when we introduce you to an installer, at no cost to you. Any contract for work is directly between you and the installer.