Get the exact warranty terms.
Ask for the panel, inverter and battery model numbers and their written warranties. Some panels offer 25-year product and 30-year performance cover, but those periods are model-specific, not universal.
Solar warranty questions answered
What do solar panel warranties actually cover?
Solar is a long-term investment. Clear warranties, an established installer and the right paperwork help you buy with confidence.
Use our eight-point checklist before signing, then explore the protection behind each promise.
Guide updated: 8 October 2026
Your solar buyer checklist
Buying solar? Check these eight things before you sign.
Separate product from performance.
A promise about panel degradation is different from protection against defects. Neither automatically covers the entire system or guarantees annual generation from your roof.
Check labour and roof access.
Who pays for diagnosis, scaffolding, removal, shipping and reinstallation? Ask for the answer in writing, alongside the workmanship guarantee.
Check who you are contracting with.
Match the legal name and company number on the quotation, contract and invoice. Check trading history and previous company connections, rather than relying on a familiar brand.
Ask existing customers.
Look for evidence of aftercare several years after installation. A long-established business is a useful signal; a record of resolving faults is stronger evidence than age alone.
Confirm the actual insured protection.
Ask which guarantee is insured, when cover starts, the limits and exclusions, and how you receive the certificate. A scheme logo alone is not proof your installation is registered.
Understand eligible credit protection.
Qualifying credit-card payments or linked finance may give Section 75 rights. Check eligibility and the payment arrangement; it does not create a blanket lifetime warranty.
Agree the handover documents.
Keep the contract, invoice, equipment serial numbers, commissioning records, registrations and insurance certificate. Store copies independently of the installer’s portal.
Start with these checks, then use the detailed evidence table when comparing quotations.
The short answer
“25-year warranty” may describe only one promise attached to one component.
A complete solar and battery system can involve the panel manufacturer, inverter manufacturer, battery manufacturer, mounting-system supplier, installer, consumer-code provider and an insurer.
Each may cover a different risk. The longest number on the quotation therefore tells you very little about the protection of the complete installation.
Ask for the remedy, not just the duration.
A replacement component is useful, but it may not include fault-finding, labour, scaffolding, shipping, removal, reinstallation or compensation for electricity that was not generated.
Six separate protections
Know which promise you are reading.
Product warranty
Normally addresses defects in materials or manufacture, subject to the manufacturer's conditions. It may offer repair, replacement, a substitute product or another stated remedy.
Check whether labour, access and shipping are included and whether the warranty must be registered.
Performance warranty
Promises that panel output will not fall below a stated degradation curve over time. It is not the same as saying the panel will remain fault-free.
Check how underperformance is measured, who pays for testing and what remedy applies if the threshold is missed.
Workmanship guarantee
Covers specified faults arising from the installer's work, rather than a manufacturing defect in the equipment. Examples may include mounting, cabling or weatherproofing issues where the written terms apply.
Confirm the duration, claim route and exclusions.
Insurance-backed guarantee
This is intended to provide separate protection for an eligible installer guarantee if the installer ceases trading, subject to the policy wording and conditions.
It is not a universal extension of every manufacturer warranty. Obtain the actual certificate and keep it safely.
Inverter warranty
Often has different terms from the panel warranty. The inverter is active power-electronic equipment, so compare the standard period, any paid extension, replacement process and labour treatment.
Check whether internet connection, approved installation or service records are conditions.
Battery warranty
May be limited by years, energy throughput, cycles, retained capacity or whichever limit is reached first. Operating temperature, installation location and software connectivity may matter.
Ask what usable capacity is guaranteed at the end of the term and how it will be tested.
Product versus performance
A panel can satisfy one warranty while failing the test for another.
If a panel suffers a covered manufacturing defect, that is generally a product-warranty question. If it still operates but produces less than the warranted degradation curve, that may be a performance-warranty question.
The performance promise is commonly misunderstood. It does not necessarily guarantee the output of your complete roof, because household generation is also affected by weather, shading, soiling, inverter availability, wiring, orientation and monitoring accuracy.
A credible claim process therefore needs evidence that separates panel degradation from other causes.
The expensive exclusions
The component may be free while reaching and replacing it is not.
Before treating a warranty as valuable, check who pays for:
✓ diagnosis and testing;
✓ an engineer's visit;
✓ scaffolding or other access equipment;
✓ removing the failed component;
✓ delivery and return shipping;
✓ installing and commissioning the replacement;
✓ making good roof finishes or cable routes;
✓ lost generation while the system is unavailable.
A quotation should not imply that all these items are included unless the written documents say so.
Before accepting a quotation
Ask for evidence against every warranty claim.
| Question | Evidence to request | Why it matters |
|---|---|---|
| Who provides the warranty? | Named legal entity and current contact details | The installer and manufacturer are not interchangeable. |
| What exactly is covered? | Full terms, not a brochure headline | Duration alone does not define the protection. |
| What is the remedy? | Repair, replacement, credit or another stated outcome | A remedy may be limited or calculated on a declining basis. |
| Who pays associated costs? | Written position on labour, access, freight and reinstallation | These costs can exceed the value of a component. |
| Does it require registration? | Registration confirmation and deadline | Some extended terms depend on timely registration. |
| What could invalidate it? | Exclusions and maintenance conditions | Location, alterations, internet access or unauthorised work may matter. |
| What if the installer closes? | Insurance-backed certificate and policy terms | An installer promise may otherwise disappear with the business. |
| How do I prove the equipment? | Invoice, model numbers, serial numbers and commissioning pack | A future claim needs a traceable system record. |
If the installer stops trading
Separate manufacturer cover from the installer's own obligations.
A manufacturer warranty may remain available through the manufacturer's UK claim route or an authorised service network. That does not automatically replace the installer who diagnosed faults, supplied labour or guaranteed workmanship.
An insurance-backed guarantee may respond if its qualifying event and policy conditions are met. It should never be assumed from a logo on a quotation: obtain the certificate, check the insured company name and read the policy.
Your statutory consumer rights are separate from a voluntary manufacturer's warranty. For an individual dispute, use current consumer advice and obtain legal guidance where necessary.
The company behind the promise
A proven history matters. Check the legal business as well as the brand.
An installer with ten or more years of continuous trading can offer valuable evidence of experience and staying power. It is not a guarantee of future solvency or good workmanship. Ask for older installations, customer references and examples of how warranty problems were resolved.
Search Companies House using the company number on your contract. Review incorporation date, status, filing history and directors’ other company appointments. “Twenty years’ experience” may describe an individual’s career rather than the age of the business offering your guarantee. Filed records are a starting point, not proof of financial health.
What about “phoenix” companies?
A phoenix business is a new business that emerges after a previous company fails. This can be part of a legitimate rescue. The concern for buyers is a repeated pattern of closures and fresh companies that leaves earlier customers without practical recourse against the original installer.
Repeated short-lived companies, unexplained changes of legal entity or a trading-history claim that does not match the records deserve questions. They do not by themselves prove wrongdoing. Ask who will honour existing guarantees and request any promised transfer of obligations in writing: a similar name, website or director does not automatically make a new company responsible for the old company’s debts.
Closure does not automatically erase every protection. Manufacturer warranties, valid insurance and qualifying credit claims may offer separate routes, depending on their terms.
HIES and insurance-backed guarantees
Useful fallback protection, with a defined scope.
HIES says that when an accredited installer registers your installation, it purchases an insurance-backed guarantee on your behalf. This backs the original installer’s written workmanship guarantee, subject to the policy conditions, if the installer ceases trading or cannot honour that guarantee.
It is not automatically insurance against a panel, inverter or battery manufacturer going out of business, and it does not turn every equipment warranty into comprehensive cover. Deposit protection is a separate protection with its own conditions.
Before signing, confirm the installer’s current membership, how your installation will be registered, and when you will receive the insurance certificate. HIES states that no cover is in place until you receive the insurance-backed guarantee certificate. Its stated conditions include a completed, defect-free installation, full payment directly to the named installer, and a valid contract and workmanship guarantee. Read the policy duration, cover limits, exclusions and claim trigger. Keep the certificate with your contract.
Section 75 explained
Your payment method may provide another route to a remedy.
Section 75 of the Consumer Credit Act can make a credit provider jointly liable for a supplier’s breach of contract or misrepresentation. The cash price of the eligible purchase must be more than £100 and no more than £30,000, and the required debtor–creditor–supplier relationship must exist.
A qualifying credit-card deposit can potentially protect a claim relating to the whole eligible purchase, even if the rest is paid another way. Eligible linked point-of-sale finance can also qualify. Debit cards and ordinary personal loans do not automatically provide this protection; the precise credit and payment arrangements matter.
This is a legal route for a qualifying claim, not an automatic copy of every 25- or 30-year warranty and not a promise of unlimited future cover. Payment through intermediaries can affect eligibility. Keep the contract and payment evidence, raise problems promptly and seek advice about the applicable time limits, which can differ in Scotland.
Tom Solar does not offer finance. If you arrange credit independently, ask the provider to explain eligibility and costs. The Financial Ombudsman Service explains goods and services bought on credit.
Documents to keep
A warranty is difficult to use if the system cannot be identified.
✓ signed contract and final invoice;
✓ complete quotation and system design;
✓ MCS certificate where applicable;
✓ DNO notification or approval;
✓ commissioning records and electrical certificates;
✓ panel, inverter and battery model and serial numbers;
✓ manufacturer warranty registrations;
✓ workmanship and insurance-backed certificates;
✓ monitoring login and installer handover information.
Keep copies somewhere independent of the monitoring app and the installer's customer portal.
Related guidance
Warranty duration and useful life are different questions.
A solar panel may continue producing after a warranty ends, while a long performance warranty does not guarantee that every part of the system will remain trouble-free.
Check the property and proposal
The strongest warranty cannot correct a badly designed system.
Equipment quality, roof condition, mounting, cable routes, inverter sizing, battery location and commissioning still matter. Review the complete proposal rather than allowing one warranty headline to make the decision.
Useful official guidance
Read the documents behind the sales claim.
- MCS guidance for consumers and communities
- HIES information on insurance-backed guarantees
- Insolvency Service: phoenix companies and consumer concerns
- Financial Ombudsman Service: Section 75 and purchases on credit
- Citizens Advice consumer guidance
This page provides general information, not legal advice. Warranty and policy terms vary, so check the documents issued for the actual installation.