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Solar Inverter Replacement in London
If your solar inverter has stopped, is showing a fault, or is reaching the end of its life, we can find out why and put it right: a repair where that is possible, a replacement where it isn't, or an upgrade to a hybrid inverter that is ready for a battery.
Solar Panels London replaces inverters across London and around 50 miles beyond, including on systems we did not install and on systems still on the Feed-in Tariff. We diagnose first, so you only replace an inverter that genuinely needs it, and we handle the Feed-in Tariff and network operator paperwork that goes with it.
Signs your inverter needs attention
The inverter is the part of a solar system that works hardest. It converts the DC power from your panels into the AC power your home uses, all day, every day there is light. Panels routinely outlive their first inverter, and the Energy Saving Trust puts a typical inverter life at around 10 to 15 years.
- A blank display, or no lights at all during daylight
- A red or amber fault light, or an error code on the display or in the app
- Generation at or near zero on a bright day
- An inverter that keeps shutting down on sunny days and restarting
- A system installed around 2010 to 2015 that has never had its inverter changed
Not every one of these means the inverter has failed. A monitoring app can go offline when the Wi-Fi changes, and a tripped isolator can look like a dead inverter. Our guide to the signs your solar inverter is failing explains how to tell the difference.
Please don't open the inverter or disconnect anything. The DC side of a solar system is live whenever there is daylight on the panels, and it can't be switched off at the panel. Note any error code, take a photo of the display, and leave the rest to a qualified engineer.
We diagnose before we replace
A fault code doesn't always mean the unit is finished. Before recommending a replacement we check what the system is actually doing: the inverter's fault and event history, the DC strings from the panels, the AC side and isolators, firmware, and the monitoring connection.
Sometimes the problem turns out to be elsewhere, such as a damaged cable, a failed string or a tripped breaker. If so, we fix that instead. If the inverter has failed, you get a clear explanation of the options and what each one means for your system.
Repair, replace or upgrade
Repair
Worth asking about, but often not available. Many domestic string inverters are sealed units designed to be replaced rather than repaired, and repair depends on the manufacturer still supporting that model with parts and firmware. Where a genuine repair is possible and the unit is otherwise sound, we'll tell you.
Like-for-like replacement
A new inverter of a suitable rating doing the same job as the old one. It is the simplest route, especially on the Feed-in Tariff, because your generation metering carries on exactly as before.
Upgrade to a hybrid
A hybrid inverter runs your panels and a battery, now or later. If the old inverter has to come off anyway, it is often the natural moment to get ready for battery storage. On Feed-in Tariff systems it changes how the system is metered, so we plan that with you first.
Your Feed-in Tariff and the network operator: handled
Feed-in Tariff
Ofgem's guidance allows generating equipment, including the inverter, to be repaired or replaced without affecting an accredited installation, provided it continues to meet the scheme rules. Your installed capacity is based on your panels, so a new inverter doesn't change your tariff rate.
You should tell your FIT licensee about the replacement. Where we replace with a hybrid inverter, our practice is to fit a bidirectional meter, subject to checking your system. Our guide to inverter replacement on a Feed-in Tariff system covers the detail, including deemed and metered export.
Network operator (DNO)
A type-tested replacement of the same size or smaller is notified to your network operator after it is commissioned. If the new inverter, on its own or with a battery, takes the system above 16 amps per phase, which is 3.68 kW on a single-phase supply, an application is needed and approved before the work goes ahead.
We handle whichever applies. Our guide to DNOs, system size and export limits explains the thresholds in full.
Inverters we work with
We work with FoxESS, Sigenergy, Solis and Hanchu equipment, and we still service and replace SolarEdge systems. We also diagnose and replace inverters from brands we don't install, including ones that have changed hands or left the UK market since your system went in. If your inverter needs replacing, we'll explain the options rather than defaulting to the brand we stock.
What happens on the day
- We isolate the system safely, on both the DC and AC sides.
- We remove the old inverter and fit the new one, reusing sound cabling where it is safe to.
- We commission and test the system, and check it is generating.
- We set up the monitoring app in your name, so you can see what your system is doing.
- We complete the electrical certification and the network operator notification, and give you what you need to tell your FIT licensee.
We'll tell you at the inspection how long the work will take and whether anything else on the system needs attention at the same time.
Common questions
Will replacing my inverter stop my Feed-in Tariff payments?
Not in itself. Ofgem allows equipment to be repaired or replaced provided the installation continues to meet the scheme rules. Tell your FIT licensee about the change.
Will a bigger inverter increase my FIT?
No. For the Feed-in Tariff your installed capacity is based on your panels, not your inverter.
Can you replace an inverter on a system you didn't install?
Yes. A large part of our servicing work is on systems another company installed, and you don't need the original paperwork to book.
Should I add a battery at the same time?
It is often a sensible moment, because the old inverter has to come off anyway. Whether it is worth it depends on your usage and tariff. Our guide to adding a battery to existing solar panels explains the options.
Is it worth repairing an old inverter?
Sometimes. If the manufacturer still supports the model and the rest of the unit is sound, a repair can make sense. If it is near the end of its expected life, a repair may only postpone the replacement. We'll give you an honest view.
Do you cover my area?
We cover all of London and roughly 50 miles beyond it. If you are not sure, ask.
Book a solar system inspection
Tell us what the inverter is doing, or what it has stopped doing, and we'll arrange a visit. We'll find out what has failed and tell you honestly whether to repair, replace or upgrade.
Monday to Friday, 9am–5pm. We reply to enquiries within one working day.
Solar Panels London. Last reviewed 3 November 2026. Feed-in Tariff and grid connection rules are current at the date of review, and what any individual system needs is always subject to an inspection. Illustrations are for explanation and do not show a specific installation.
Is my home suitable for solar panels?
During your free home survey we'll assess your roof's orientation, pitch and condition, along with any shading from trees or neighbouring buildings. We'll tell you honestly whether solar is a good fit for your home, and if it is, we'll design the system around getting the best out of it.
How much can I save on my energy bills?
It depends on how much electricity you use, when you use it, the size and orientation of your system, and whether you add a battery to store daytime solar for the evening. Rather than quote a typical figure, we model the expected generation and savings for your home as part of your free quote, using your actual bills and roof.
How long does installation take?
We aim to get your system up and running as quickly as we can. After your survey, installation is typically scheduled within 2–8 weeks, though the exact timing depends on things like DNO approval, scaffolding, roof access and how complex the system is. We agree a date with you once those are confirmed.
Do you offer finance options?
Yes, finance may be available, subject to status. Ask us about it when you request your quote.
What does the quote cover?
Your written quotation lists everything included for your home – the panels, inverter, any battery, mounting, scaffolding where your home needs it, electrical work, DNO paperwork and MCS certification – with one total price. What’s on the quotation is what you pay, with no hidden extras.
Do you offer a guarantee?
We offer a 6-year workmanship warranty, insurance-backed through IWA, on top of the manufacturer warranties covering the panels, inverter and battery. Annual servicing, monitoring checks and fault finding are available as an aftercare service. If something isn’t right with our work, we come back and put it right.
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