Solar Inverter Repair and Replacement
Red light, error code, blank screen or zero output? We diagnose, repair and replace solar inverters from any installer, across England, Wales and Scotland.
Repairs you can rely on
- MCS registered
- NAPIT registered
- TrustMark approved
- Any installer’s system
- In-house engineers
Call us on 0800 156 0191
Monday to Friday, 9:00am–5:00pm
Is this what you’re seeing?
A red or orange warning light on the inverter
An error code or fault message on the display
A blank display, even in daylight
Clicking, buzzing or humming that’s louder than usual
The monitoring app says the inverter is offline
Zero output on a bright day
The inverter feels very hot, or its fan never seems to stop
The solar breaker in the consumer unit keeps tripping
If there’s a code or message on the screen, write it down or take a photo. It often tells us what the fault is before we arrive.
Call 0800 156 0191 or use the fault finder further down this page. If the solar breaker keeps tripping, leave the system switched off until an engineer has looked at it.
What’s going wrong with your inverter
The inverter turns the direct current (DC) produced by your panels into the alternating current (AC) your home uses and exports. It also watches the panels and the grid all the time, and shuts itself down if anything falls outside safe limits. That’s why an inverter problem often looks like a system that has simply stopped: the inverter is protecting itself, or you.
Why inverters fail
- Heat. Inverters in lofts, garages and cupboards with poor airflow run hot, and heat ages electronics faster.
- Wearing components. Capacitors and cooling fans wear out over the years, and they’re a common cause of failure in older inverters.
- DC isolation faults. If moisture gets into a connector or a cable is damaged, the insulation between the DC wiring and earth breaks down. The inverter detects this and refuses to connect to the grid.
- Grid voltage. Where the local grid voltage runs high, the inverter disconnects to stay within its limits. You may see it switch off and on through a sunny day.
- Firmware and communication. Some faults are software problems, or a lost link to the monitoring platform, and can be cleared with an update or a reconfiguration.
Repair or replace?
We always diagnose before recommending anything. Some faults — a damaged connector, a tripped isolator, a firmware problem, a failed fan — can be put right without replacing the inverter. Others, particularly internal failures on older units, can’t be repaired sensibly, and replacement is the better choice. We’ll tell you which situation you’re in, explain why, and give you a clear written quote before any work starts. If the inverter is still covered by the manufacturer’s warranty, we’ll help you make the claim.
What a replacement involves
A like-for-like replacement uses the same or an equivalent model with the same capacity. We isolate the system safely, swap the unit, recommission it, reconnect the monitoring and test the output.
Sometimes the original model has been discontinued, or it makes sense to move to a hybrid inverter so a battery can be added later. If the new inverter changes the system’s rated output, the Distribution Network Operator (DNO) has to be notified, and we take care of that. We also provide the certification and documentation for the new inverter, including an updated MCS certificate where one is needed, so your paperwork stays in order for insurance, feed-in tariff payments and selling your home.
We install inverters as well as repair them, so we know how these units fail and which replacements hold up.
Brands we repair
Common faults and error codes, brand by brand:
SolarEdge inverter repair
Isolation faults, optimisers and error codes.
Fronius inverter repair
State codes, overheating and no feed-in.
SMA inverter repair
Red lights, insulation faults and event codes.
Growatt inverter repair
Error codes, PV isolation and No AC Connection.
Solis inverter repair
OV-G-V, NO-Grid and leakage alarms.
SolaX inverter repair
IE codes, isolation and backup power faults.
We also repair most other makes, including older and discontinued models.
Why L&R Renewables
Any installer’s system
It doesn’t matter who fitted your inverter or whether they’re still trading. We work on all the common brands, old and new.
Certified, in-house engineers
We’re MCS and NAPIT registered and TrustMark approved, and our own engineers carry out every job.
Honest about repair versus replacement
If a repair will do the job, that’s what we recommend.
England, Wales & Scotland
We cover England, Wales and Scotland.
Frequently asked questions
Is my inverter still under warranty, and who makes the claim?
Manufacturer warranty lengths vary by brand and model, and some were extended when the system was installed. The warranty belongs to the product, so it usually still applies even if your installer is no longer trading. Manufacturers normally want an engineer’s diagnosis and evidence of the fault before approving a claim. We can diagnose the fault, gather what the manufacturer needs and deal with them for you.
My installer has gone bust. Can you still help?
Yes. We don’t need the original installer to be involved, and we provide the certification and documentation for any new inverter we fit.
How long do solar inverters last?
Inverters don’t usually last as long as the panels. Many string inverters need replacing somewhere around the ten to fifteen year mark, though heat, ventilation and grid conditions make a big difference. It’s normal for a system to need a new inverter at some point in its life.
Can you replace my inverter with a different brand?
Usually, yes, as long as the new inverter suits the panels and the way they’re wired. There are exceptions: systems with SolarEdge power optimisers on each panel need a SolarEdge inverter, unless the optimisers are replaced too. We check compatibility before recommending anything.
My inverter has been discontinued. What happens now?
We find a current model that suits your panels, wiring and any battery plans. If it changes the system’s rated output, we notify the DNO and update the documentation for you.
What does “isolation fault” mean?
It means the inverter has measured a drop in the insulation between the DC wiring and earth — often caused by water in a connector, a damaged cable or a failing isolator. The inverter disconnects for safety. Repeatedly resetting it won’t fix the cause, so it’s worth having the system tested.
Related pages
Solar panel repair
Diagnosis and repair for the whole system, from any installer.
Solar panel servicing
An annual health check that catches faults early.
Solar panel cleaning
Safe, professional cleaning with a system check included.
Tell us what your inverter is doing
Answer four quick questions — including the make and any error code — and leave your details, and we’ll call you back to arrange a visit. Prefer to talk? Call 0800 156 0191, Monday to Friday, 9:00am–5:00pm.
Solar fault finder
What’s happening with your system?
What make is your inverter?
Roughly how old is the system?
Where is the property?
Leave your details and we’ll be in touch to book your initial visit.
We’ll ring you to talk it through and arrange a convenient time. Your answers above go with your enquiry, so you won’t have to repeat them.
We’ll talk through what’s happening and book your initial visit. If it’s urgent, call 0800 156 0191.
Rather talk now? Call 0800 156 0191 — free from UK landlines and mobiles.
You can also reach us through our contact page.