When solar panels are not working, the first useful step is not to argue with the installer. It is to build a clear evidence pack. A strong complaint letter shows what was promised, what the system is doing now, who has been contacted, and which documents are missing.
This guide is for homeowners who have already noticed a problem such as no generation, very low output, an inverter fault, a battery that will not charge, roof damage after installation, or missing handover paperwork. Equisure Direct does not inspect solar systems or repair equipment. The point here is to help you organise the information needed for formal complaint and dispute correspondence.
Start with the exact symptom
Write down the problem in plain language before you gather documents. Keep it specific:
- The panels show no generation in the app or meter.
- Generation is much lower than the sales estimate or forecast.
- The inverter shows a fault code, red light or warning.
- The battery is not charging or is not holding charge.
- The installer has not supplied the MCS certificate, DNO paperwork, warranty documents or handover pack.
- A roof leak or damage appeared after the installation.
Do not guess the technical cause unless an electrician, installer or surveyor has put it in writing. A complaint that says “the system has generated 40 percent less than the quote forecast over the last twelve months” is stronger than one that tries to diagnose the panels.
Save screenshots and meter readings
If the monitoring app still works, take screenshots before anything changes. Capture:
- daily and monthly generation graphs;
- inverter or battery status screens;
- fault codes and warning messages;
- export readings, if your app shows them;
- the date and time on each screenshot.
If you have a smart meter, export meter, generation meter or inverter display, photograph the readings. Keep the original image files if possible, because they preserve date information. Where the system has worked in the past, gather before and after screenshots so the drop in output is clear.
Compare output against the sales paperwork
Most solar complaints turn on the gap between the sales promise and the real performance. Find the documents that show what you were told before you agreed:
- quote or proposal;
- savings estimate;
- generation forecast;
- payback period calculation;
- roof survey or design;
- system size in kWp;
- number and model of panels;
- inverter and battery model;
- finance agreement, if finance was arranged.
Do not rely only on memory. Put the quoted figures beside the actual figures from the app, bills or generation meter. If the salesperson made promises by email, text or WhatsApp, save those messages as well.
Check the handover pack
Missing paperwork can be part of the complaint in its own right. It can also explain why the problem has become hard to resolve. Look for:
- MCS certificate;
- electrical certificate;
- DNO notification or approval record;
- building control document, where supplied;
- product warranties;
- workmanship warranty;
- insurance backed warranty, if one was provided;
- user manuals;
- final invoice and payment receipts.
MCS publishes consumer information about certified installations at mcscertified.com. If your paperwork says the installer was a member of a consumer code, check the current complaint route before escalating. RECC now directs new consumer disputes through Green Homes Dispute Resolution, and HIES describes its consumer protection and alternative dispute route at hies.org.uk.
Keep a contact timeline
Make a simple timeline before writing the complaint. Include:
- date the system was sold;
- date it was installed;
- date you first noticed the fault or shortfall;
- every call, email, visit and promised callback;
- names of people you spoke to;
- what the installer said would happen next;
- what actually happened.
If calls were not followed up in writing, send a short email now confirming what was discussed. A written record is easier to use later than a call note.
Work out who should receive the complaint
The right recipient depends on the problem.
Start with the installer for installation faults, low generation, missing paperwork, roof damage or poor handover. The installer should have the first chance to respond in writing.
If the panels were bought on credit card or finance arranged through the installer, there may also be a lender complaint. The Financial Ombudsman Service explains that consumers normally complain to the financial business first, then can approach the ombudsman if the business sends a final response or eight weeks pass without resolution. See financial-ombudsman.org.uk/consumers/how-to-complain.
If the issue is unfair trading, misleading sales conduct or unsafe work, Citizens Advice explains how reports can be passed to Trading Standards. That route can help enforcement bodies spot patterns, but it is separate from your own complaint letter. See citizensadvice.org.uk/consumer/get-more-help/report-to-trading-standards/.
What to ask for in the letter
Keep the request practical and linked to the evidence. Depending on the problem, you might ask for:
- a written explanation of the fault;
- missing certificates and warranty papers;
- a repair plan with dates;
- a response to the difference between quoted and actual generation;
- a copy of the sales call notes or survey record;
- the installer response needed before a consumer code or lender complaint.
Avoid broad accusations. The letter should say what happened, what document proves it, what has already been tried, and what response is now requested.
What Equisure can prepare
Equisure Direct prepares formal complaint and dispute correspondence from the customer’s paperwork. That can include a letter to the installer, a finance provider, or the correct dispute route once the evidence is clear.
The service is not a roof survey, electrical inspection or repair service. If the cause of the fault is unclear, an independent technical report may still be needed. The letter then uses that report alongside the contract, quote, app data, bills and messages.
Quick checklist before you complain
- Screenshots of app output, inverter warnings and battery status.
- Photos of meter readings.
- The quote, contract and sales estimate.
- Finance agreement or credit card evidence, if relevant.
- MCS certificate, electrical certificate and DNO paperwork, or notes showing they are missing.
- Warranty and insurance backed warranty documents.
- Messages, emails and call notes with the installer.
- A short timeline of the fault and every contact attempt.
- Any independent inspection, roofer or electrician report.
Once these are in one place, the complaint can be written with less guesswork and fewer gaps.
Related services
Explore our letter writing service by area, or learn more about complaint letter writing, dispute correspondence, and Subject Access Requests.