Advice · 4 min read · Updated 6 November 2026
Does cleaning solar panels void the warranty? A guide for UK owners
The two warranties most panels come with
Most solar panels sold in the UK carry two separate warranties, and cleaning can affect each in a different way. Knowing which is which makes it much easier to read the small print.
| Warranty type | What it usually covers | Typical length |
|---|---|---|
| Product warranty | Defects in materials and manufacture, such as failed junction boxes, delamination or faulty frames | Often 10 to 25 years |
| Performance warranty | A minimum share of the panel's rated output over time | Often 25 to 30 years, guaranteeing roughly 80 to 90 percent of rated output by the end |
| Installer workmanship warranty | The installation itself, such as fixings, cabling and roof work | Often 2 to 10 years, depending on the installer |
Inverters, batteries and optimisers usually have their own warranties, typically shorter than the panels. These are guide figures and the documents for your own system are what count.
What manufacturers usually say about cleaning
Panel manufacturers publish installation and maintenance manuals, and nearly all of them include a short section on cleaning. The wording varies, but the guidance is remarkably consistent across brands.
- Use soft brushes, sponges or cloths rather than anything abrasive
- Use clean water, ideally low in minerals, so it does not leave spots
- Avoid high-pressure water jets aimed at the glass, seals and frame edges
- Avoid harsh solvents, strong alkaline or acidic cleaners and scouring products
- Do not stand, walk or kneel on the panels
- Avoid cleaning hot panels with cold water in strong sun, which can stress the glass
Some manuals give a maximum water pressure or a recommended water temperature range. If you cannot find the manual, the manufacturer's website usually has it as a download under the panel model number, which is printed on the label on the back of each panel and is often listed on your installation paperwork.
Cleaning methods that can put cover at risk
A warranty is rarely cancelled simply because panels were cleaned. The risk comes when a cleaning method causes damage that the manufacturer can then say was not a defect.
- Pressure washers, which can strip the anti-reflective coating and force water past seals
- Scrapers, wire wool and abrasive pads, which scratch the glass
- Household detergents and degreasers, which can leave residues and attack seals
- Walking or kneeling on panels, which can cause micro-cracks in the cells that only show up later as lost output
- Rooftop cleaning that disturbs cables, connectors or mounting rails
Micro-cracks are the most common hidden problem. They cannot usually be seen with the naked eye, but they can reduce output and create hot spots. If a manufacturer finds them during a claim, it may argue they came from foot traffic rather than a defect.
How to protect your warranty when you clean
- Find and save the maintenance manual for your panel model
- Choose a pure water, soft brush method from the ground where possible
- Ask any cleaner to confirm the method and that no one will stand on the panels
- Keep a simple log with the date, method used and before and after photos
- Note anything unusual, such as cracked glass or loose cables, and report it promptly
- Keep your installation certificate and handover pack somewhere safe
Photos are especially useful. A dated photo of clean, undamaged panels shows the condition of the array at that point, which can help if a fault appears later.
Bird proofing, monitoring kit and other add-ons
Bird proofing mesh is normally fitted with clips that grip the panel frame lip, so nothing is drilled into the panels. This is the widely used method because it avoids altering the panels. Anything that drills, glues or screws into a panel frame is far more likely to raise questions with a manufacturer.
If you are adding anything to the array, such as mesh, optimisers or monitoring devices, check the installer and manufacturer guidance first. Changes to wiring or the inverter should only be made by a qualified installer or electrician.
Home insurance is a separate question. Some policies cover panels as part of the building, but accidental damage during DIY cleaning may be excluded or need specific cover, so check your policy wording.
If something goes wrong
If you notice a cracked panel, scorch marks, a junction box fault or a sudden drop in output, stop cleaning and contact your installer. If the installer has stopped trading, an MCS-certified installer can usually inspect the system and help with a manufacturer claim. Have your panel serial numbers, purchase date, installation certificate and any cleaning records ready, as manufacturers commonly ask for them.
Performance warranty claims usually need evidence that a panel is producing below the guaranteed level, which normally means testing by an installer rather than simply comparing your monthly figures. Dirt and bird fouling lower output too, so a manufacturer may ask for the panels to be cleaned before testing. That is another reason to keep a record of when and how the panels were last cleaned.
Bear in mind that many manufacturers sell through distributors, and claims often have to go through the original installer. If a manufacturer has left the UK market, cover can be harder to use, so an insurance-backed guarantee from the installer, if you have one, may be the more useful document.
Frequently asked questions
Will a professional clean affect my solar panel warranty?
Not if the cleaner uses a method that matches the manufacturer's guidance, which is usually purified water and soft brushes with no one standing on the panels. Ask the cleaner to confirm their method before booking, and keep a dated note and photos of the clean. Problems arise when damaging methods such as pressure washing or scraping are used.
Do I have to clean my panels to keep the warranty valid?
Most product and performance warranties do not require a set cleaning schedule for homes. However, some manuals say the owner should keep panels reasonably clean, and heavy soiling or shading is not a manufacturing defect. Commercial maintenance contracts are different and may set cleaning intervals, so check the contract if you have one.
Where can I find my panel warranty documents?
Look in the handover pack from your installer, which usually includes the MCS certificate, an electrical certificate and product data sheets. The panel model and serial number are on a label on the back of each panel. Manufacturers usually publish warranty terms and maintenance manuals on their websites under the model number.
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