How to Make a Solar Warranty Claim in New Zealand

To make a solar warranty claim in New Zealand, you need to first identify which of the three warranties applies (product, performance, or workmanship), gather your original contract, invoices, and monitoring data, and lodge a written claim with your installer first, not the manufacturer. If your installer has gone out of business (a real and growing issue in the NZ market), you can claim directly with the panel, inverter, or battery manufacturer's local NZ representative, and the Consumer Guarantees Act 1993 still protects you regardless of what the warranty document says. Most legitimate claims for faulty inverters or underperforming panels are resolved within 4 to 12 weeks if you document properly and stay polite but firm.

This guide walks through the practical steps a Kiwi homeowner takes when something goes wrong with a solar system, whether it's a dead inverter, a panel producing well below spec, or a dodgy roof penetration that's started leaking. We'll cover the three warranty types, what each one actually covers, and how to navigate the claim process without getting stonewalled.

This article is for homeowners who already have a system installed. If you're still researching, our ownership and aftercare pillar is the better starting point.

What Solar Warranties Actually Mean for NZ Homeowners

Solar warranties in New Zealand are a bit of a layered cake. There isn't one single document that covers everything; there are three separate warranties, each from a different party, each with different terms and different claim processes. This catches a lot of homeowners off guard when something goes wrong.

On top of those three warranties, you also have statutory protection under the Consumer Guarantees Act 1993 (CGA) and the Fair Trading Act 1986, both administered by the Commerce Commission. These laws override anything written in a warranty document that's less generous, which is a powerful tool that many installers quietly hope you don't know about.

Here's the short version of who's on the hook for what:

• Product warranty, covers physical defects in the panels, inverter, or battery. Issued by the manufacturer, typically 10 to 25 years.
• Performance warranty, covers the output of the panels over time. Issued by the panel manufacturer, typically 25 to 30 years on a sliding scale.
• Workmanship warranty, covers the installation itself (mounting, wiring, roof penetrations). Issued by your installer, typically 5 to 10 years.

Knowing which warranty applies to your specific problem is the first move. Get this wrong and you'll waste weeks chasing the wrong party.

The Three Warranty Types Explained

Product Warranty (Manufacturer)

The product warranty covers manufacturing defects. If a panel develops microcracks, the junction box fails, the backsheet delaminates, or an inverter's capacitors blow, this is the warranty you claim under. It's issued by the manufacturer (LONGi, Jinko, REC, Sungrow, Fronius, Enphase, Tesla, BYD, etc.) and is honoured by their NZ distributor.

Typical product warranty terms in the NZ market:

• Tier-1 mono panels: 12 to 25 years (premium brands like REC offer 25)
• String inverters: 5 to 12 years (Fronius and Sungrow commonly 10)
• Micro-inverters: 25 years (Enphase is the standout here)
• Hybrid inverters: 5 to 10 years
• LiFePO4 batteries: 10 years or a defined cycle/throughput count, whichever comes first

Important point: a product warranty almost never covers the labour to replace the faulty item. So if your inverter dies in year 9 of a 10-year warranty, the manufacturer ships a new unit, but you may pay an electrician 400 to 800 dollars to swap it in. Read the fine print.

Performance Warranty (Panel Manufacturer Only)

The performance warranty is unique to solar panels. It guarantees that the panels will still produce a certain percentage of their original rated output after a set number of years. A typical performance warranty looks like this:

• Year 1: minimum 97 to 98% of rated output
• Year 25: minimum 84 to 87% of rated output (Tier-1 standard)
• Year 30: minimum 87 to 92% on premium N-type TOPCon and HJT panels

This warranty is harder to claim against because you need monitoring data showing the panel is producing below the guaranteed curve, adjusted for irradiance and temperature. This is why our guide on monitoring your solar production matters so much: without records, you can't prove a performance claim.

Workmanship Warranty (Your Installer)

The workmanship warranty is the one most likely to leave you exposed if your installer disappears, and unfortunately we've seen a few NZ solar installers fold in recent years. It covers things like:

• Roof penetrations and flashing (leaks)
• Mounting rail security and panel clamping
• DC and AC cabling, conduit, and isolators
• Switchboard work and earthing
• Commissioning errors (wrong inverter settings, incorrect string sizing)

A 10-year workmanship warranty is the gold standard in NZ. Five years is the minimum we'd consider acceptable. Anything less and you're carrying risk the installer should be carrying. The CGA gives you some recourse even if the workmanship warranty has expired, provided the fault is something a reasonable consumer wouldn't expect in that timeframe.

Step-by-Step: How to Make a Warranty Claim

Step 1: Identify and Document the Problem

Before you contact anyone, gather evidence. Take dated photos. Screenshot your monitoring app (FusionSolar, SolarEdge, Enphase Enlighten, Fronius Solar.web, etc.) showing the issue. Note the date and time you first noticed the problem.

If output has dropped, work through our solar output troubleshooting guide first to rule out the obvious (shading, dirty panels, tripped isolator). You don't want to waste a warranty claim on something a quick clean would fix; our panel cleaning and maintenance guide covers the basics.

Step 2: Pull Your Paperwork

Find these documents before you ring anyone:

• Original sales contract or quote (lists what was supplied and at what price)
• Final invoice (the legal proof of purchase under the CGA)
• Electrical Certificate of Compliance (CoC) and the Electrical Safety Certificate (ESC), both required under WorkSafe regulations
• System commissioning report (often a single PDF including string voltages and inverter serials)
• Panel and inverter serial numbers (on the equipment, also on the commissioning report)
• Manufacturer warranty certificates
• Monitoring data exports if available

If you can't find these, ask your installer to resupply them. They're legally required to provide the CoC and ESC and most reputable installers keep digital copies on file for at least a decade.

Step 3: Contact Your Installer First (Always)

Even if you suspect a manufacturing fault, your installer is your first port of call. There are two reasons:

1. Under the CGA, your contract is with the installer, not the manufacturer. They're the party with the legal obligation to fix things.
2. Manufacturers will typically refuse a direct claim from a homeowner and redirect you to the installer who purchased the equipment.

Put your claim in writing (email is fine) even if you've also rung them. State the issue, attach your photos and monitoring data, reference your invoice, and ask for a written response within 10 working days. Keep it polite and factual. The paper trail matters if it ever escalates.

Step 4: The Site Visit and Diagnosis

A reputable installer will book a site visit within a couple of weeks. They'll check the system, log into the inverter, and either fix it on the spot (often the case with comms issues or a tripped isolator) or diagnose a hardware fault that needs a manufacturer claim.

You should not be charged a call-out fee if the fault is covered under warranty. If they try to charge you to diagnose a warranty issue, push back and reference the CGA. Some installers will charge a diagnostic fee that gets refunded if a fault is confirmed, which is a reasonable middle ground for older systems.

Step 5: The Manufacturer Claim

If the installer confirms a manufacturing defect, they lodge the claim with the manufacturer's NZ distributor on your behalf. You shouldn't have to deal with the manufacturer directly. The installer:

• Submits serial numbers, photos, and fault description
• Receives a Return Merchandise Authorisation (RMA)
• Removes the faulty unit, ships it back, and installs the replacement

Replacement units usually arrive in 2 to 8 weeks depending on stock in Australia or NZ. Major brands like Fronius, Sungrow, and Enphase hold local stock and can replace inverters within days; obscure brands may take months.

Step 6: If Your Installer Won't Play Ball, or Has Gone Bust

This is unfortunately common enough that we treat it as a real scenario, not an edge case. If the installer is unresponsive, ignoring your claim, or has wound up the business:

1. Contact the manufacturer's NZ distributor directly. Most Tier-1 panel and inverter brands honour their product warranty even if the original installer is gone. You'll likely need to pay another sparkie to do the swap.
2. Raise a CGA claim with the Disputes Tribunal (claims under 30,000 dollars, filing fee around 60 dollars).
3. If the installer is still trading but unresponsive, contact Consumer NZ for advice and consider a complaint to the Commerce Commission.
4. If a master electrician issued the CoC, you can also escalate to Master Electricians who maintain a workmanship guarantee for member firms.

What This Means for You

For the ROI Pragmatist

Warranty claims protect the financial case for your system. A failed inverter in year 8 is a 2,500 to 4,500 dollar hit that, properly claimed, costs you only the labour. If you're still in the buying phase, factor warranty length into your quote comparison; a system with a 10-year inverter and 10-year workmanship guarantee is materially more valuable than one with 5-year coverage, even at the same price. The solar ROI calculator lets you model what an unplanned mid-life inverter replacement does to your payback.

For the Tech-Savvy Optimiser

You're already monitoring output, so a performance warranty claim is realistic for you. Export your monitoring data quarterly, save the CSV. Compare your system's PR (performance ratio) against the manufacturer's stated degradation curve. If you're more than 3% below the curve over a full year (irradiance-normalised), you have a credible performance claim. Most homeowners never collect the data to make one.

For the Eco-Conscious Family

Your concern is usually longevity and not having to chuck panels in landfill in 15 years. The good news: Tier-1 panel performance warranties to year 25 mean panels are designed to last well past most mortgages. The practical step is to keep all your warranty paperwork in a single labelled folder (digital or physical) so the next owner of your home, or you in 15 years, doesn't have to start from scratch.

What Installers Won't Tell You

A few honest truths the industry tends to gloss over:

• "25-year warranty" usually means the panel's performance warranty, not its product warranty. Always ask: is the warranty on the physical panel 12 years or 25?
• Labour is rarely covered. A "10-year inverter warranty" often means the manufacturer ships you a new unit; you still pay an electrician to install it. Ask the installer to clarify in writing.
• Workmanship warranties are only as good as the installer's longevity. A 10-year workmanship guarantee from a one-man-band trading for 18 months is not the same as a 5-year guarantee from a 15-year-old company.
• Roof leaks from solar mounts are a classic dispute zone. The installer will often blame the roof; the roofer will blame the solar installer. Photograph penetrations during install and request that flashing details are recorded in the commissioning report.
• The CGA outranks the warranty document. If your inverter fails at year 7 with a 5-year warranty, you can still argue under the CGA that a reasonable consumer expects an inverter to last longer than 5 years given the price.
• "Pro-rata" replacement clauses can be ugly. Some battery warranties refund a pro-rata of original price after a certain point, not a free replacement. Read the schedule carefully.

Frequently Asked Questions

How long do I have to make a solar warranty claim in NZ?

Each warranty has its own term (product 10 to 25 years, performance 25 to 30 years, workmanship 5 to 10 years). Beyond those, the Consumer Guarantees Act 1993 gives you protection for as long as a reasonable consumer would expect the goods to last, which for a quality solar system is at least 10 to 15 years for inverters and 20+ years for panels.

What if my solar installer has gone out of business?

You can still claim directly with the manufacturer's NZ distributor for product warranty issues. For workmanship issues, your options are the Disputes Tribunal under the CGA, a CGA-based claim against any successor business that bought the failed installer's assets, or in some cases a Master Electricians workmanship guarantee if your installer was a member at the time of installation.

Does the manufacturer pay for the electrician to install the replacement?

Usually no. Most product warranties cover only the replacement hardware, not labour. Some premium brands (Enphase, certain Fronius dealer packages) include labour for the first few years. Always ask your installer to highlight the labour position in writing.

How do I prove a panel is underperforming?

You need monitoring data over at least 12 months showing output below the manufacturer's degradation curve, irradiance-adjusted. The cleanest evidence is per-string or per-panel monitoring (SolarEdge, Enphase). For string inverter systems, you may need an installer to do an IV curve trace on individual panels.

Is a workmanship warranty transferable if I sell my house?

Most are, but you need to formally transfer the warranty with the installer at the point of sale. Some installers charge a small admin fee. Manufacturer product and performance warranties are usually attached to the system serial numbers and transfer automatically.

What documents should I keep for warranty purposes?

Sales contract, final invoice, Certificate of Compliance, Electrical Safety Certificate, commissioning report, manufacturer warranty certificates, panel and inverter serial numbers, and exports of your monitoring data at least once a year. Keep them digitally backed up, not just on the installer's app.

Can I claim under the Consumer Guarantees Act if my warranty has expired?

Yes, in many cases. The CGA requires goods to be of acceptable quality and durable for a reasonable period given price and type. A 12,000 dollar inverter failing at year 6 is unlikely to meet that test, regardless of what the manufacturer's 5-year warranty says. The Disputes Tribunal hears these cases.

How long does a typical warranty claim take?

Straightforward inverter replacements from major brands take 2 to 6 weeks. Panel claims requiring testing take 4 to 12 weeks. Disputed claims or claims against a non-responsive installer can take 3 to 9 months including Disputes Tribunal time.

Do I need a lawyer for a solar warranty dispute?

Almost never. The Disputes Tribunal is specifically designed for consumers without lawyers and handles claims up to 30,000 dollars. Consumer NZ and Citizens Advice Bureau both offer free guidance.

Where to Go From Here

The single most valuable thing you can do today is open a folder (digital or physical) and put every warranty document, invoice, and certificate from your solar install in one place. Add a quarterly monitoring export. That folder is your insurance policy against installer disappearance, manufacturer disputes, and the slow forgetting that happens over a 25-year asset.

If you're still troubleshooting a specific issue, start with our output troubleshooting guide. If you want to get on top of monitoring before you ever need a warranty claim, our monitoring app guide walks you through the major platforms. And if your install is still ahead of you, the ownership and aftercare pillar is the broader map.