When you buy a solar system, the paperwork often mentions warranties of 25 years or more. It sounds reassuring, but many owners aren’t sure what those warranties actually cover, who they’d need to contact, or what happens when something goes wrong.
This article explains the different warranties that typically come with a solar system, what they usually cover, and what they usually don’t. It’s general information only, and your own warranty documents always take priority.
A Solar System Usually Has Several Warranties
There isn’t one single “solar panel warranty.” A typical UK system carries several, each from a different source:
- Product warranty (from the panel manufacturer). Covers manufacturing defects in the panel itself. Commonly 10 to 25 years.
- Performance warranty (from the panel manufacturer). Guarantees a minimum power output over time. Commonly 25 to 30 years.
- Inverter warranty (from the inverter manufacturer). Covers faults in the inverter. Commonly 5 to 12 years, with paid extensions often available.
- Workmanship warranty (from your installer). Covers problems caused by the installation, such as mounting, wiring or roof fixings.
- Battery warranty (from the battery manufacturer). Covers faults in the battery, if you have one. The length is set by the manufacturer.
Lengths vary by brand, and by when your system was installed, so the figures above are a guide only.
Product Warranty vs Performance Warranty
These two are often confused, but they protect against different things.
The product warranty covers the panel as a physical object: defects in materials or manufacturing that stop it working properly, such as cell failure or faults in the glass or junction box.
The performance warranty is a promise about power output. All panels lose some efficiency as they age, and this warranty guarantees they’ll still produce at least a specified percentage of their original output after a set number of years. It’s about meeting that guaranteed minimum, not about your system’s day-to-day generation.
Why the Inverter Warranty Is Usually Shorter
Panel warranties are measured in decades, but inverter warranties are usually measured in years. That reflects the fact that the inverter does more work and is typically the first major component to need attention. If you want to understand what that looks like in practice, see our guide to common inverter faults, and for how long components tend to last, see how long solar panels last.
Many solar inverter brands offer paid warranty extensions, so it’s worth checking whether yours does and whether it needs to be registered.
What a Warranty Usually Doesn’t Cover
Every warranty has its own terms, but these are commonly excluded or fall outside what the manufacturer covers:
- Damage from external causes, such as storms, falling debris, or impacts. Home insurance may be relevant here instead.
- Damage from pests. Nesting birds can chew or foul wiring, which is generally not a manufacturing defect. Bird proofing helps prevent this.
- Normal wear and gradual ageing within the limits allowed by the performance warranty.
- Faults caused by poor installation, which would fall under the installer’s workmanship warranty rather than the manufacturer’s.
- Issues arising from unapproved repairs or modifications. Some warranties specify who can work on the equipment.
What If Your Installer Has Gone Out of Business?
The panel and inverter warranties come from the manufacturers, so they don’t depend on your installer still being in business. A workmanship warranty is different. Many installers back theirs with an insurance-backed guarantee that applies if the company stops trading, so it’s worth checking your paperwork to see whether you have one.
How to Make a Claim
- 1Find your documents: Gather your warranty paperwork, installation certificate and purchase details.
- 2Work out which warranty applies: A panel defect goes to the panel manufacturer, an inverter fault to the inverter manufacturer, and an installation problem to your installer.
- 3Record the fault: note error codes, dates, photos, and any generation data that show the problem.
- 4Get it diagnosed: A proper diagnosis from a qualified engineer helps establish what’s failed and why, which is often what the manufacturer will want to see. Our solar PV repair team can diagnose faults on existing systems.
- 5Check the conditions: Some warranties require registration or have conditions around servicing, so read the terms carefully.
