Repairs · Guide
How long do solar inverters last?
Most solar inverters last 10 to 15 years. The Energy Saving Trust advises planning to replace one after around 12 years.
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Why it fails first
Why the inverter fails before the panels.
Panels usually last 25 years or more, so most systems need at least one new inverter in their lifetime. For systems fitted in the early feed-in tariff years, that time is now.
The panels are simple, solid-state and sealed. The inverter is not. It converts the panels’ DC power into AC for your home every daylight hour, which means:
- It runs hot. Heat is the main thing that ages the capacitors and other electronics inside.
- It has moving parts. Many models have cooling fans that wear out.
- It is sensitive to the grid. It has to check the grid voltage continuously and disconnect when it goes outside set limits.
- It is exposed. Units in hot lofts, on sunny walls or in dusty garages have a harder life than those in a cool, ventilated space.
Inverter types
String inverters, hybrids, microinverters and optimisers.
- String inverter. One box serves the whole array, and it’s the most common type on UK homes. When it fails, the whole system stops. This is the type the 10–15 year guide mostly applies to.
- Hybrid inverter. A string inverter that also manages a battery. It has a similar life, and it’s the usual choice when a failed inverter is replaced and the owner wants to add storage.
- Microinverters and power optimisers. Small units fitted behind individual panels. They are designed for longer lives. When one fails, you usually lose the output of one panel rather than the whole system, which makes the fault easy to miss unless you check your monitoring.
Warning signs
Signs your inverter is failing.
- A red or amber light, or an error code, especially one that keeps coming back.
- A blank display in daylight.
- Clicking on and off, repeated restarts, or beeping.
- Louder fan noise than usual, or a hot smell.
- Generation well below the same month last year.
- A system that works in the morning but drops out on bright afternoons.
- A solar breaker or RCD that keeps tripping.
Some of these point to problems outside the inverter, such as damp in a connector, a tripped isolator or high grid voltage. That is why testing before replacing matters. Our checklist for solar panels not working covers the safe checks you can make yourself. For brand-specific codes, see SolarEdge, Fronius, SMA, Growatt, Solis and SolaX.
Repair or replace
Repair or replace?
It depends on the fault and the age of the unit.
Worth repairing:
- faults caused outside the inverter (a wet isolator, a loose or damp DC connector, a tripped protection device, incorrect settings after a grid change);
- failed fans;
- some faults on newer models still supported by the manufacturer.
Usually worth replacing:
- internal power or control board failures on older units, particularly models that are no longer made and have no spare parts;
- an inverter that has failed more than once.
Our engineers test the system first, so you don’t replace an inverter that wasn’t the problem. We offer same-week inverter repair or replacement on SolarEdge, SMA, Fronius, Growatt, Solis, SolaX and other makes. You get a clear written quote before any work starts. See inverter repair.
Replacement
What replacing an inverter involves.
- The panels stay as they are. A new inverter is matched to your existing array. You don’t need new panels.
- It’s usually a day’s work or less, done by one of our own engineers, with the system tested and handed back to you generating.
- Monitoring is set up again on the new unit, so you can see what the system is producing.
- It’s a good moment to add a battery. A hybrid inverter can run battery storage now or later, without replacing the inverter a second time.
- Feed-in tariff payments: Ofgem’s rules let you repair or replace equipment such as the inverter without affecting your accreditation, as long as the installation still meets the scheme rules. Let your FIT supplier know about the change; we’ll give you the details they need. See feed-in tariff meter readings.
Looking after it
How to help your inverter last longer.
- Keep its ventilation clear. Don’t store boxes against it or cover the vents.
- If it’s in a hot loft or on a south-facing wall, ask about shading or better ventilation at your next service.
- Keep outdoor units’ covers and cable entries sealed against rain.
- Have the fault log reviewed once a year. Repeated warnings often show up long before the inverter stops. See solar panel maintenance.
Sources: Energy Saving Trust, Solar panels: costs, savings and benefits explained (updated August 2026).
Questions
The things people ask before they ring.
Not answered here? Call 0800 156 0191, Monday to Friday, 9:00am–5:00pm.
How long do solar inverters last?
Typically 10 to 15 years. The Energy Saving Trust suggests planning to replace one after around 12 years. Microinverters and power optimisers are designed to last longer, but individual units can still fail.
Is it worth replacing the inverter on an old solar system?
Usually, yes. The panels on an older system are normally still generating well; the inverter is the part that has worn out. Replacing it gets the whole array working again, and it is a good moment to consider a hybrid inverter that can run a battery.
Why is my solar inverter beeping?
Many inverters beep or sound an alarm when they detect a fault, for example an earth or insulation fault on the panel side. Check the display or app for an error code and note it down. If the alarm repeats, call an engineer rather than resetting it again and again.
Do you replace inverters that another company installed?
Yes. We repair and replace inverters on systems fitted by any installer, including installers who are no longer trading. We cover England, Wales and Scotland.
Ready when you are
Inverter showing a fault?
We’ll call you back to talk it through, and you get a clear written quote before any work starts. Mon–Fri 9:00am–5:00pm.