Product, performance and workmanship warranty: three different things

A product warranty covers the panel being faulty. A performance warranty covers the panel still making close to the power it promised. A workmanship warranty covers the installation itself: the mounting, the wiring, the holes in your roof. Different companies hold them, they run for different lengths, and a claim under one is not a claim under another.

The three at a glance

Two of those three are held by companies overseas that have never met you. Only the third is held by the business that came to your house.

Product warranty

This is the one people mean when they say "the warranty". A part is faulty, so the maker replaces it.

Every major component has its own, so a normal system carries at least three: panels, inverter, and the battery if there is one. They are different lengths and they start on different dates, so they do not expire together.

Real examples from documents we have read:

• Canadian Solar carries 25 years of product cover on the current TOPHiKu6 residential modules, checked 16 August 2026.
• SolarEdge carries a standard 12 year inverter term, starting at the earlier of installation or four months from shipment, checked 30 July 2026.
• Alpha ESS gives five years as standard on the battery, with a paid extension to ten that has to be bought within 30 days of installation, checked 30 July 2026.

Notice how differently the clocks start. That is normal, and it is where most of the surprises come from.

Product warranties usually have conditions

The years on the brochure are the best case, not the only case. Two examples:

GoodWe gives ten years on many inverters, but only while the unit is connected to the SEMS portal and uploading generation data. Without that, the term is five. Tesla registers a Powerwall at commissioning, but the ten year term needs the unit to stay online: if the connection drops and is not restored within 45 days of Tesla's written request, cover ends at 48 months.

Neither of those brands sends you a warning. That is why they are worth checking once rather than discovering later.

Performance warranty

Panels lose a little output every year. A performance warranty is the manufacturer's promise about how little.

It is written as a percentage of the panel's rated output at particular years, and the exact curve is specific to the model. It is a separate promise from the product warranty and it usually runs longer.

The cleanest illustration in the whole catalogue is Silfab. Its performance warranty runs 30 years. Its product warranty is 12 years from delivery, and becomes 25 years only if the installation is registered through Silfab's portal within 180 days of purchase. Same brand, same panel, two entirely separate promises with two entirely different requirements attached. Registration changes one of them by 13 years and does not touch the other at all.

Canadian Solar splits the same way: 25 years product, 30 years performance on the current residential modules.

Batteries have their own version of this. Alpha ESS runs five years of standard cover alongside ten years on battery performance. FranklinWH promises 70 percent capacity retention at the end of the term on aPower 2 and aPower S, which are 15 year products. A battery that still switches on but holds far less than it should is a performance question, not a product one.

Performance claims are harder than product claims

A product claim is usually obvious. The inverter is dark, the battery will not charge, the panel has visible damage.

A performance claim asks you to prove a number. That means a measurement taken under conditions the manufacturer will accept, compared against the guaranteed output for that model in that year. Shading, dirt, a failed optimiser, a string fault or a hot week all look like underperformance and none of them are a panel defect.

In practice this means a performance claim needs a competent installer or service company involved before you file anything. It also means monitoring data matters. If your system has been reporting for years, you have a history. If it has not, you are starting from nothing.

Workmanship warranty

This is your installer's promise about their own work: the racking, the roof penetrations, the cabling, the isolators, the commissioning.

We do not publish terms for it, and we will not, because there is no manufacturer document to check. Workmanship terms are whatever your contract says. Lengths vary enormously between companies. Read your own contract; it is the only source that binds anybody.

Two things about it are worth knowing.

It dies with the installer. A promise from a company that no longer exists is not worth anything. If your installer has closed, this is the warranty you have lost, and the manufacturer warranties are the ones you still have. There is a full walkthrough of that situation here.

It is often what covers the labour on somebody else's part. Which brings us to the thing nobody explains at the sale.

The gap that costs money: labour

A product warranty usually covers the part, not the work of fitting the part.

So the maker ships you a new inverter for free, and then you pay a company to diagnose the fault, get on the roof, remove the old unit, fit the new one and commission it. If your workmanship warranty is still live, that labour is often covered. If it is not, the bill is yours.

Two manufacturers in this catalogue narrow that gap themselves, and they are the exceptions rather than the rule:

• REC carries 240 months of labour cover on the Alpha Pure-R line. That is 20 years, and it is the longest labour term here by a distance.
• Enphase reimburses $200 per truck roll plus $25 per replaced microinverter in the United States, with a paid Labor Protection Program extension that stretches labour cover to five or ten years from activation.

Everything else in the catalogue carries either 12 months of labour cover or none at all. Manufacturer labour cover is also not the same thing as your installer's workmanship warranty, even though both end up paying for a visit. One is the maker reimbursing work on their part. The other is the installer standing behind their own work.

If you want to see what a visit actually costs against what a brand pays back, the truck roll calculator does that sum.

Which one is your problem?

• The inverter is dead, the battery will not charge, a panel has failed: product, and it goes to the manufacturer.
• The system works but is making noticeably less than it should, and it is not shading or dirt: performance, and it needs a measurement before it goes anywhere.
• Water is coming in around a mount, a cable is chafing, a rail has moved: workmanship, and it goes to your installer.
• Nothing is broken yet and you want to keep it that way: check the conditions on the brands you own at panel warranties, inverter warranties and battery warranties.

Whichever it is, the file is the same. Serial numbers, install date, proof of purchase, and evidence of the fault. The claim checklist will build the list for your brand and part.