Solar inverter replacement — when to replace and what it costs
Solar inverters last 10–15 years on average. When yours fails, behaves erratically, or is past economic repair, replacement is the right path. This guide covers how to decide between repair and replacement, what a good replacement looks like, realistic costs, and what the installation process involves.
Inverter replacement is also an opportunity to upgrade from a string inverter to a hybrid model — enabling battery storage and EPS backup without a full system replacement.
The inverter replacement service covers diagnosis (if needed), old unit decommission, new unit supply and fitting, commissioning, settings migration, and post-installation testing — all confirmed in writing before work begins.
View inverter replacement service → Book nowShould you repair or replace your inverter?
This decision depends on the inverter's age, the nature of the fault, the cost of repair versus replacement, and whether you want to upgrade capability at the same time. Use this guide as a starting point — always diagnose the fault before deciding.
Always diagnose before replacing. What looks like an inverter failure is sometimes a configuration error, a tripped RCD, or a fault in the DC array rather than the inverter itself. A remote diagnostic (£75) confirms whether the inverter is actually faulty before you commit to a £795+ replacement. The diagnostic cost is not wasted — it is applied to the repair or replacement fee if you proceed with us.
How long do solar inverters last?
Inverter lifespan varies considerably by brand, installation environment, and operating pattern. Most modern units come with 10–12 year warranties; well-maintained units from quality brands can exceed 15 years.
Choosing a replacement inverter
Replacement is an opportunity to upgrade. Whether to replace like-for-like or upgrade to a hybrid model depends on your goals.
Like-for-like replacement (string inverter → string inverter)
The simplest option — replace the failed unit with the same model or current generation equivalent. Low installation complexity, no changes to DC string wiring, settings migration straightforward. Best option when the system is well-designed, relatively new, and you have no plans to add battery storage.
Upgrade to hybrid inverter (string → hybrid)
Replace the string inverter with a hybrid model (GivEnergy, Sunsynk, Growatt SPH, SolaX, Fox ESS). This enables DC-coupled battery storage without a separate battery inverter, EPS backup power, and smarter energy management. Requires checking DC string voltage and current compatibility with the new hybrid unit — may need string reconfiguration.
Same-brand upgrade (e.g. old GivEnergy → new GivEnergy)
Upgrading within the same brand (e.g., GivEnergy AIO 2.6 kW to AIO 5.0 kW) often allows monitoring account transfer and retains settings familiarity. DC string compatibility must be checked. If you have an existing GivEnergy battery, the new inverter must support the same battery model — confirm firmware compatibility before ordering.
What inverter replacement involves
A full residential inverter replacement typically takes 4–6 hours on-site. See the inverter replacement service page for full details of what's included.
Confirm DC string voltage and current compatibility with the new unit. Record existing settings (export limit, monitoring configuration, battery parameters if applicable). Confirm wall space and mounting requirements for the new unit. Order the replacement unit and any additional components (mounting brackets, cabling adaptors).
DC strings isolated at roof level. AC supply isolated at consumer unit. Battery (if present) safely powered down. Old inverter disconnected and removed. Wall mounting cleaned and prepared for the new unit. All DC and AC connections documented before disconnection.
New inverter mounted and earthed. DC strings reconnected and polarity verified. AC connection made to consumer unit (new MCB/RCBO installed if required). Battery connection re-established if applicable. All connections torqued to manufacturer specification.
Inverter powered up and commissioned to grid. Country-specific parameters set (UK G99 compliance: voltage, frequency, reactive power curves). Export limit configured. Monitoring portal account created or migrated. Battery parameters (if applicable) configured to match previous charge/discharge schedules and tariff windows.
Full generation test — confirm inverter is producing at expected levels. Battery charge/discharge test (if applicable). EPS test (if EPS circuit present). Post-installation report provided documenting: new unit model and serial number, configuration settings, test results, and DNO notification status.
Inverter replacement costs
Supply and fit. Like-for-like string inverter replacement. Includes commissioning and DNO variation.
Supply and fit. Upgrade to hybrid for battery compatibility. May require CT clamp repositioning.
Larger or three-phase units. Cost assessed on enquiry — depends on model and string configuration.
Commercial three-phase string and central inverters. SMA, Huawei, Solis, SolarEdge, GoodWe. See commercial O&M.
All costs include: old unit decommissioning and disposal, new unit supply and fitting, G99 variation DNO notification, commissioning to UK grid parameters, export limit configuration, monitoring setup, and post-installation report. No hidden extras. Written quote before any work starts.
Related pages
Ready to book? The service page covers full details, pricing, and has a direct enquiry form.
Not sure if the inverter is faulty? Diagnose first before committing to a replacement.
Replacing with a hybrid? Here's what battery addition involves after the inverter swap.
A new hybrid inverter also opens the door to EPS backup power. What EPS installation involves.
Inverter replacement — frequently asked questions
10–15 years for most inverters, with quality brands (Fronius, SMA) often exceeding 15 years. Most manufacturers provide 10–12 year warranties with extension options. Budget brands may fail within 5–8 years. Lifespan shortens in hot environments, locations with unstable grid voltage, and where dust blocks ventilation. Well-maintained, cool-running inverters regularly outlast their warranty period.
Repair if: inverter is under 8 years old, fault is software/configuration, or component repair costs under 30–40% of a new unit. Replace if: over 10 years old and out of warranty, discontinued model with no parts available, repair cost exceeds 40% of replacement, or you want to upgrade to hybrid for battery/EPS capability. Always diagnose before deciding — a remote diagnostic at £75 often reveals whether it is a configuration issue rather than hardware failure.
String inverter replacement (supply and fit) £795, typical £700–£995. Hybrid inverter replacement (with battery upgrade option) from £995, typical £995–£1,200. Three-phase and larger residential units £1,200+. Commercial three-phase inverter replacement from £1,995 — we work with all major commercial brands. See commercial O&M for more detail. All costs include old unit removal and disposal, new unit commissioning, DNO G99 variation, and post-installation report. No hidden extras — confirmed in writing before work starts.
Yes — a G99 variation form must be submitted to your DNO. For like-for-like replacement with no capacity change, variations are usually approved automatically within 2–4 weeks. If you are upgrading inverter capacity, adding battery storage, or changing export settings, additional detail is required. We handle the DNO notification as part of the replacement service.
If replacing like-for-like with the same brand, monitoring can usually be migrated to the new unit's serial number in the same portal account. Changing brand means a new monitoring account and loss of historical data from the old portal (though historical data may be exportable). We set up the new monitoring connection, create the account, and confirm data is logging correctly before sign-off.
Ready to replace your inverter?
The inverter replacement service covers everything — diagnosis if needed, old unit removal, new unit supply and installation, DNO notification, and commissioning. One fixed price, no hidden extras.