Solar Inverter Replacement Cost UK: Prices & When to Replace
Inverter died, or output creeping down? It’s the one part of a solar system you should expect to replace. Here’s what it costs in 2026, the warning signs, and the upgrade worth considering while you’re at it.
The short answer
A solar inverter replacement costs £600–£1,500 installed for a like-for-like string inverter in 2026 (£700–£1,100 for a standard 3–4kW system), £1,200–£2,000 for a hybrid, and £150–£350 per unit for microinverters. Diagnosis runs £80–£150, usually credited against the work. It’s a half-day job, and London and the South East add 10–25%.
The context that matters: inverters last 10–15 years against panels’ 25–30, so one replacement is normal and expected — not a system failure. And it’s the ideal moment to consider a hybrid upgrade that makes your system battery-ready. Our repairs guide covers the wider who-pays picture; this page is the inverter specifics.
What this guide covers
The inverter is the hardest-working component in your solar system — converting DC to AC every daylight hour for years on end — and it’s the part most likely to need replacing within the system’s life. If yours has failed, or your generation’s been quietly slipping, you’re in the majority of solar owners who’ll face this at some point, especially the millions whose systems went up in the 2010–2016 Feed-in Tariff boom and are now reaching inverter-replacement age.
The good news: it’s a well-understood, half-day job with clear pricing, and — handled right — it’s a chance to improve your system, not just restore it. Here’s everything you need before getting quotes.
Solar inverter replacement costs in 2026
| Replacement type | Installed cost (2026) | Notes |
|---|---|---|
| String inverter, 1–2kW system | £500–£850 | Entry-level, single-phase |
| String inverter, 3–4kW system | £700–£1,100 | The most common home replacement |
| String inverter, 5–6kW+ | £900–£1,500 | Larger capacity units |
| Hybrid (battery-ready) inverter | £1,200–£2,000 | The upgrade route — see below |
| Microinverter (per unit) | £150–£350 | Only the failed unit(s) need replacing |
| Diagnosis / call-out | £80–£150 | Usually credited if you proceed |
The equipment is roughly £400–£800 of a string replacement, labour £200–£400, with the rest down to complexity: a ground-floor swap onto existing brackets sits at the low end, while new mounting, consumer-unit changes or scaffolding push toward the top. Microinverters flip the maths — no single point of failure, so only the dead unit gets replaced (£150–£350) rather than a whole central inverter, one of the panel-level architecture trade-offs. Getting two or three quotes matters here: prices for identical hardware vary by hundreds of pounds.
7 signs your inverter needs replacing
- 1. No generation on sunny days — your monitoring shows zero or near-zero output when it should be producing. The clearest sign.
- 2. Red or amber LED on the inverter itself — not just the app; the light on the unit indicating a fault state.
- 3. Error codes on the display — look the specific code up in your manual, or quote it to an engineer for diagnosis.
- 4. Repeated shutdowns and restarts — the inverter cycling off and on, unable to hold a stable state.
- 5. A steady, unexplained drop in output — year-on-year generation falling with no new shading, soiling or weather cause. Subtler than outright failure, and worth a professional efficiency check (DC-in vs AC-out).
- 6. Unusual noise or overheating — buzzing, humming or a unit running notably hot suggests failing internals.
- 7. Visible rust, scorch marks or water ingress — physical damage to the casing or wiring: a safety concern, not just efficiency. Get it looked at promptly.
One reassurance before you assume the worst: some “faults” aren’t the inverter. A dropped WiFi dongle (system fine, app blind), a tripped breaker, or new shading from a grown tree can all mimic inverter trouble. A proper diagnosis — £80–£150, often credited against any work — confirms it before you spend on a replacement.
Repair or replace?
The 12-year / 40–50% rule
Replace rather than repair if the unit is 12+ years old, or if a repair quote exceeds 40–50% of the cost of a new inverter. Beyond that age, a repair buys you months on tired electronics while a new unit brings 5–10 years of warranty, better efficiency, and the hybrid option. Newer inverters (under ~8 years, ideally still in warranty) are usually worth repairing or claiming. And the economics of replacing are strong regardless: if the panels are sound, a £700–£2,000 inverter restores a system generating £400–£900 of value every year — it pays for itself fast. Full system replacement only makes sense if the panels themselves are damaged or the array is tiny by modern standards.
Warranty and who pays
Before paying for anything, check whether someone else should. Three routes, in order:
- Manufacturer warranty — inverter warranties run 5–12 years depending on brand, and some extend free on registration. If yours is a Solis registered for the full 10 years, for instance, a failure inside that window may be covered. Dig out your registration and serial number first.
- Installer’s workmanship warranty — if the original install was recent and the fault traces to installation, this may apply.
- The exception that catches people: a manufacturer that no longer exists. GivEnergy’s administration in April 2026 left owners with void warranties — if that’s you, the full who-pays picture (Consumer Rights Act, Section 75) is in our GivEnergy and repairs guides.
The hybrid upgrade: replacement’s silver lining
Here’s the opportunity most owners miss. When you’re already paying for the labour, access and an inverter, upgrading from a plain string unit to a hybrid inverter costs only a little more — and it makes your system battery-ready, so you can add storage later without replacing the inverter again. If you’ve ever thought about a battery, an inverter failure is quietly the cheapest moment to prepare for one.
The maths: a hybrid runs £1,200–£2,000 installed versus £700–£1,500 for like-for-like — a modest premium that saves you a second inverter job down the line, and opens the door to the evening-bill savings a battery brings. Pair a hybrid now with a 5kWh battery this year or in three years’ time, on your schedule. Our inverters guide explains the string-vs-hybrid difference in full if you’re weighing it up.
The FIT-system warning
Critical for the 2010–2016 crowd: a like-for-like inverter replacement does not affect your Feed-in Tariff payments — but increasing your system’s capacity can. If your replacement stays like-for-like, you’re fine; if you’re tempted to add panels or significantly change the setup at the same time, tell your FIT licensee first, because those payments are often worth more than the whole repair. Keep the paperwork for any inverter change too — licensees sometimes ask. When in doubt, a like-for-like swap (or a hybrid of matching AC output) keeps your FIT income safe.
Inverter replacement: pros & cons of upgrading vs like-for-like
✓ Upgrade to hybrid when…
- You want a battery now or later
- The access & labour are already being paid for
- Your old inverter was basic / out of warranty
- You’re staying in the home long-term
- The premium (£300–£500) beats a future second job
✓ Stick to like-for-like when…
- You’re on a FIT and want zero payment risk
- Budget is tight and a battery isn’t on the horizon
- The system is small or nearing end-of-life anyway
- You’re selling the house soon
- A matching unit keeps everything simplest
Frequently asked questions
How much does it cost to replace a solar inverter in the UK?
£600–£1,500 installed for a like-for-like string inverter (£700–£1,100 for a standard 3–4kW system), £1,200–£2,000 for a hybrid, and £150–£350 per unit for microinverters. Diagnosis is £80–£150, usually credited. London and the South East add 10–25%.
How long do solar inverters last?
Typically 10–15 years, against the panels’ 25–30 — so one replacement in a system’s life is normal. Over 12 years old, it’s worth a replacement quote even while working, since planned beats emergency.
What are the signs it needs replacing?
No generation on sunny days, a red/amber LED on the unit, error codes, repeated shutdowns, a steady unexplained output drop, unusual noise or heat, and visible rust or scorch marks. Any of these warrants a diagnosis — though a dropped dongle or tripped breaker can mimic a fault.
Repair or replace?
Replace if it’s 12+ years old or the repair exceeds 40–50% of a new unit’s cost; repair or claim if it’s newer and possibly under warranty. Either way, if the panels are sound, a new inverter restoring £400–£900/year of generation pays back fast.
Will it affect my Feed-in Tariff?
A like-for-like swap won’t; increasing capacity can. Tell your FIT licensee before any change beyond a straight replacement, and keep the paperwork. This matters most for 2010–2016 FIT-era systems now needing inverters.
Should I upgrade to a hybrid inverter?
Often worth it — for a modest premium over like-for-like, it makes your system battery-ready so you can add a battery later without replacing the inverter again. Replacement time is the cheapest moment to prepare for storage.
A routine job — and a quiet upgrade chance
The bottom line: Budget £700–£1,100 for a standard string swap, expect one in your system’s life, and check the warranty before you pay. If a battery’s ever crossed your mind, spend the small premium on a hybrid and thank yourself later.
Get my free replacement quotes →The verdict
An inverter replacement isn’t a sign your solar system has failed — it’s the expected mid-life service on the one component built to wear out first. At £700–£1,100 for a standard string swap, restoring hundreds of pounds a year of generation, the maths is straightforward: if the panels are sound, replace and carry on.
The only real decision is like-for-like versus a hybrid upgrade — and for anyone who might ever want a battery, the hybrid is the quiet bargain, since you’re already paying for the visit. Check your warranty first, protect any FIT payments with a like-for-like AC output, and compare a few quotes — identical hardware varies by hundreds between installers.
Compare free replacement quotes from MCS-certified installers →
Important
Going Solar UK is an introduction service, not an installer. We don’t diagnose, supply, or fit inverters ourselves — quotes come from the MCS-certified installers we introduce you to. Prices are indicative Q3 2026 UK ranges and vary by system, brand, access and region; always get a professional diagnosis and quotes before proceeding. Feed-in Tariff, warranty and Consumer Rights outcomes depend on your specific circumstances — confirm with your licensee, manufacturer or a qualified adviser. Treat all solar DC wiring as live.
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.