How to Complain About a Solar Installer (UK 2026)

A solar installation going wrong is stressful, expensive, and confusing all at once. Maybe the panels aren’t generating what you were promised. Maybe there’s water coming through your roof. Maybe the installer took your deposit, did half the job, and stopped answering the phone. Whatever’s happened, the good news is that the UK has a proper system for putting things right – and it’s stronger than most people realise.

Here’s the honest version of how to complain, who to go to, and in what order. The system works in stages: you start with the installer, then escalate to MCS, then to independent dispute resolution if needed. Skip a stage and you’ll get bounced back, so the order matters. Most complaints get sorted well before court is ever mentioned.

This guide walks through every step, the exact contacts and deadlines you need, what evidence to gather, and what to do in the worst cases – an installer who’s gone bust, or one who’s ignoring you completely. We’ll also cover the things most guides miss: how to use your monitoring app as evidence, where your home insurance and credit card fit in, and what to do before the job even starts to protect yourself.

The most common solar complaints

Most solar installs go smoothly. But when they don’t, the problems tend to fall into a handful of familiar buckets. Knowing which one you’re dealing with helps you frame your complaint and pick the right evidence.

• Poor workmanship. The big one – panels fitted crookedly, cables left hanging, a mounting job that leaks. Under the law, work has to be done with reasonable care and skill, and sloppy work fails that test.
• Underperformance. Your system is generating far less than quoted – sometimes shade nobody surveyed for, sometimes a badly wired system or a fault. Your monitoring app is your best friend here.
• A missing MCS certificate. The panels are fitted but the paperwork never turned up – which means no Smart Export Guarantee payments, money out of your pocket every year.
• Delays. The install drags on for weeks past the agreed date, or scaffolding sits on your drive for a month with no one showing up.
• Damage to your property. Cracked tiles, a leak that appears after the work, damaged brickwork, or a mess left behind. If the installer caused it, they’re responsible for putting it right.
• The installer has gone quiet. You’ve called, you’ve emailed, and you’re getting nothing back. Frustrating – but you have routes that don’t depend on the installer cooperating.

The complaint process, step by step

The UK system is built as a ladder. You climb it one rung at a time, and each rung has to be tried before you reach the next.

Step 1: Complain to your installer first

This is non-negotiable, and there’s no way around it. Every complaint has to start with the installer – MCS and the dispute services will send you straight back if you haven’t done this first. Put your complaint in writing, and email is best because it timestamps everything. Be clear and specific:

• What the problem is – describe it plainly, with dates.
• What you want done – a repair, a redo, a refund, or a price reduction.
• A reasonable deadline – give them time, but not forever.

Allow 14 days for a response as a sensible maximum. They may not fix everything in that window, but they should at least come back with a plan of action. Keep copies of everything regardless, because if this doesn’t work, that paper trail becomes your case. One useful line to include: mention that the work should meet the standard set by the Consumer Rights Act 2015, which requires services to be carried out with reasonable care and skill. A calm, specific written request often gets a constructive response – reputable installers don’t want a formal dispute any more than you do.

Step 2: Escalate to MCS

If your installer doesn’t respond, fobs you off, or fails to put things right, and they’re MCS certified, your next stop is MCS itself. Here’s a genuinely helpful thing about the current system: MCS acts as your single point of contact. You raise the complaint once with them, and they pull in the right organisations behind the scenes – the installer’s certification body and their Consumer Code. You don’t have to chase five different bodies yourself. You can raise a complaint with MCS by:

• Online form at the MCS website, or live chat on their site.
• Email: [email protected]
• Phone: 0333 103 8130
• Post: MCS, First Floor, Violet 3, Sci-tech Daresbury, Keckwick Lane, Daresbury, Cheshire, WA4 4AB

To help them investigate, have ready the details of what went wrong, clear dated photos, your supporting documents (contract, quote, correspondence), what you’d like done to put it right, and a willingness to let the installer back in to fix things. That last point matters – the process is aimed at getting the work put right, so you need to be open to giving the installer (or another firm) access to remediate.

On timing: MCS acknowledges your complaint within 5 working days, then updates you at least every 10 working days while they investigate, aiming to resolve most complaints within 8 weeks. At the end, you get a written outcome – a summary, the investigation details, their decision and reasoning, any actions taken, and how to escalate further if you’re still unhappy.

Step 3: Escalate to independent dispute resolution (ADR)

If you’ve been through the MCS process and you’re still not satisfied – or your installer disagrees with the proposed fix – your complaint can become a formal dispute. Alternative Dispute Resolution (ADR) is a way to settle a dispute without going to court: an independent expert reviews the whole case and makes a decision. It’s a referee who isn’t on anyone’s side, and it’s designed to be far faster and cheaper than a courtroom.

MCS itself isn’t accredited to run dispute resolution, so it hands eligible cases to its ADR partner: the Dispute Resolution Ombudsman, operating as the Furniture & Home Improvement Ombudsman (FHIO). For eligible disputes, ADR is free and funded by MCS. You can escalate to ADR within 12 months of MCS concluding your complaint, if any of these apply:

• You’ve finished the MCS complaints process and you’re still dissatisfied.
• You or your installer disagree with the proposed resolution.
• Your complaint to MCS hasn’t been resolved within 12 weeks.
• Your contract was entered into under the redeveloped MCS installer scheme.

There’s a wrinkle for older contracts. If your contract with an MCS installer was signed on or after 1 January 2025, ADR applies where the installer has confirmed in writing that they agree to engage and will comply with the outcome. If your contract predates 1 January 2025, you reach ADR through the installer’s Consumer Code instead – which brings us to the next point.

Where RECC, HIES and GHDR fit in

This part changed recently, so it’s worth being clear about, because a lot of older advice online is now out of date. Consumer Codes are organisations that set extra rules for installers to protect buyers, on top of the basic MCS standards. The two you’ll come across in solar are RECC (Renewable Energy Consumer Code) and HIES. If your installer is a member of one, that gives you an additional route to dispute resolution.

You can reach GHDR directly by phone on 0204 616 0015, by email at [email protected], or online at ghdr.org.uk by selecting “Raise a Dispute.” So which route is yours? It comes down to your contract date and your installer’s memberships:

• Contract before 1 January 2025: reach ADR through your installer’s Consumer Code – via GHDR if they’re a RECC member, or through HIES if they’re a HIES member.
• Contract on or after 1 January 2025 (MCS redeveloped scheme): MCS routes you to FHIO for ADR.
• Existing RECC complaint filed before 20 January 2026: RECC continues to handle it, and your caseworker stays your contact.

If you’re not sure which applies, start with MCS – they’ll tell you the right path and make sure your complaint is tracked across the relevant bodies.

What “legally binding” ADR actually means

You’ll see the phrase “legally binding” thrown around, and it’s worth understanding what it does and doesn’t mean – because this is where a lot of the real power sits. When an ombudsman or ADR expert makes a decision, the outcome is legally binding on the installer. For MCS installers under the redeveloped scheme, the installer is legally obliged to comply. That’s a serious lever: they can’t simply shrug and ignore a decision that goes against them.

What to do if your installer has gone bust

This is the nightmare scenario, and the solar market has seen a fair few firms collapse. If your installer has gone into administration or vanished, the complaint ladder above doesn’t help – you can’t complain to a company that no longer exists. But you’re far from out of options.

• Check your workmanship warranty. Reputable installers back their work with an insurance-backed guarantee (IBG), underwritten by a third-party insurer, so it survives even when the installer doesn’t. If you have one, contact the insurer directly – the details should be in your handover pack.
• Use Section 75 if you paid by credit card. One of the strongest protections you have, and most people don’t realise how powerful it is.
• Check for a chargeback if you paid by debit card. Debit cards don’t get Section 75, but chargeback may recover money for services not provided. It’s weaker and has tighter time limits (usually 120 days), so act fast.
• Claim on your product warranties directly. Your panels and inverter carry manufacturer warranties separate from the installer, so if the kit itself fails you can often claim directly with the manufacturer.
• Get another MCS installer to assess and finish. A new certified installer can inspect what’s there, tell you what’s wrong, and complete the job – and their written assessment becomes useful evidence for any warranty or Section 75 claim.

Collecting evidence: build your case early

A complaint stands or falls on evidence. The stronger your paper trail, the faster and better your outcome – so start gathering from the moment you spot a problem, not weeks later when memories have faded. Here’s what to collect:

• Dated photographs. Clear photos of the problem from several angles. If it’s a leak or damage, photograph it as it develops – timestamps matter.
• All correspondence. Every email, text and letter. If you speak on the phone, follow up with an email summarising what was said – that turns a verbal exchange into a written record.
• Your contract and quote. These set out what you were promised – system size, expected generation, price, timeline. They’re the yardstick you measure the actual work against.
• The original sales materials. If you were quoted a specific annual generation figure and you’re falling well short, that promise is part of your case.
• Your MCS certificate and handover pack – if you got them.
• A written assessment from another MCS installer, if you’ve had one inspect the work.

Keep it all in one folder, digital and backed up. When you escalate, being able to hand over a complete, organised file makes their job faster and your case stronger.

The new take: use your monitoring data as evidence

Here’s something almost no guide mentions, and it’s one of the most powerful tools you have – especially for underperformance complaints. Nearly every modern solar system comes with monitoring, showing you day by day and hour by hour exactly how much your panels are generating. Most people use it to feel good about their savings. You can also use it to prove a problem.

When to consider legal action

Most complaints never need a solicitor. The free routes – installer, MCS, ADR, GHDR – sort the vast majority of cases. But sometimes legal advice is the more direct path. Consider it when your installer isn’t part of any approved scheme (which cuts off the free routes), the work has caused significant property damage, you’ve paid substantial sums and the installer has gone quiet, or the contract has been fundamentally breached.

Your legal foundation is the Consumer Rights Act 2015, which says services must be carried out with reasonable care and skill, in a reasonable time, for a reasonable price. A solicitor can review your contract, tell you whether you have a viable claim, send a letter before action (a formal warning that often prompts a settlement on its own), and represent you in court if needed. For smaller sums, the small claims court handles claims up to £10,000 in England and Wales, and you can do it yourself without a solicitor. For serious cases involving big money, property damage, or an installer heading toward insolvency, get legal input early rather than late – preserving evidence and formally putting the installer on notice is far easier while events are recent.

The insurance angle most people miss

Two insurance policies can quietly save you in a solar dispute, and they rarely get mentioned.

• Your home insurance. If a botched installation causes damage – a leak that ruins a ceiling, water damage to your loft, cracked tiles letting in rain – your buildings insurance may cover the resulting damage. It won’t pay to redo the bad solar work itself, but it can cover the knock-on damage while you pursue the installer separately. Tell your insurer promptly, and check whether your policy required you to notify them of the solar install in the first place, as some do.
• The insurance-backed guarantee (IBG). This protects you even when the installer is still trading but refusing to help. An IBG stands behind your installer’s own workmanship warranty – if they won’t honour their guarantee, or can’t, the IBG insurer steps in. Always check you were given an IBG as part of your handover pack.

What your MCS certificate and handover pack should include

A lot of complaints come down to missing paperwork, so let’s be clear about what you’re owed. A proper certified install leaves you with two documents, and if either is missing, that’s a legitimate complaint in itself.

The MCS certificate should reach you within 10 working days of the job finishing. It’s the official proof your installation was done by a certified installer using approved products, recording your system size and expected generation – and you need it to claim Smart Export Guarantee payments, worth hundreds a year. No certificate, no payments. The handover pack, handed over on the day, is your system’s manual and warranty file combined. A proper pack includes:

• Product details for your panels, inverter and any battery.
• Your workmanship warranty from the installer.
• Details of your insurance-backed guarantee.
• A simple maintenance guide, and basic troubleshooting for the inverter’s lights and signals.
• System performance and generation estimates, plus wiring and system diagrams.

If these didn’t turn up, ask for them in writing. Missing documentation isn’t a minor admin slip – it affects your export income, your warranty claims, and your ability to sell the house later with proof the work was done properly.

How to protect yourself before the job starts

The best complaint is the one you never have to make. Most solar disputes trace back to choices made before the first tile was lifted – so a little care upfront saves a world of pain later.

• Only use an MCS or Flexi-Orb certified installer. Check their name on the MCS “Find an Installer” tool before you sign, and again just before work starts. This single step unlocks your export payments and your free dispute routes.
• Pay your deposit by credit card. Even a small deposit gives you Section 75 protection on the entire purchase – the cheapest insurance you’ll ever get against an installer going bust.
• Get everything in writing before work begins. The specification, price, expected generation, timeline, warranty terms, and what happens if something goes wrong. Verbal promises evaporate; written ones don’t.
• Confirm you’ll get an insurance-backed guarantee. Ask for it explicitly, in writing, before you commit.
• Don’t sign under pressure. “This price is only good today” is a classic warning sign. A legitimate quote holds for a reasonable period.
• Insist on a proper survey, including a shade assessment. Many underperformance complaints start with a survey that was skipped or rushed.
• Keep every document from day one. Your quote, contract, emails and sales materials are the foundation of any future complaint.

Do these seven things and you’ve removed the causes behind the vast majority of solar disputes before they can happen.

Frequently asked questions