How to Choose an Accredited Installer: A Buyer's Checklist
What accreditation actually verifies in each market, the questions that separate a good installer from a good salesperson, and the red flags in a quote.
Most of the money lost in this industry is lost at the quote stage, not because the equipment was bad but because the installer was never checked. Accreditation is the first filter, not the last.
What accreditation means in each market
- United Kingdom — MCS. Certifies the design and installation against published standards, and is required for grant eligibility, export payments and most green mortgages. You can check a certificate number against the public register.
- United States — NABCEP. A voluntary certification for installers and designers, combined with state licensing and utility interconnection rules. NABCEP credential numbers are verifiable directly with the body.
- Australia — CEC. Clean Energy Council accreditation is required for the federal certificate rebate and confirms the installer has completed the required design and safety training.
- Canada — recognised provincial certification alongside CSA/NRCAN equipment standards, with rebate eligibility tied to certified installers in most programmes.
Ask for the scheme and the number, then check it yourself. Our directory listings mark installers whose accreditation has been verified by our team.
Beyond the badge
A certificate proves training. It does not prove that the company will still be trading in ten years, which matters because the warranties are long.
Check:
- Years trading and company registration details.
- Public liability and workmanship insurance, with a certificate you can see.
- Who actually does the work — in-house crews or subcontracted labour.
- Reviews over time, not a single burst of five-star reviews.
- A physical address and a landline, not only a mobile number.
Questions that reveal the difference
- Will you do a heat loss calculation or roof survey before quoting? A phone-only quote is a guess.
- What is the exact model, and why that one for my property?
- Who handles grants, grid connection and certification — and what happens if the claim is rejected?
- What is excluded from this price? Scaffolding, electrical upgrades and radiator changes are the usual omissions.
- What is the deposit, and what are the cancellation terms?
- Can I speak to a customer whose installation is two years old, not two weeks old?
Red flags in a quote
- A price that is dramatically below every other quote, with no itemisation.
- Pressure to sign on the day, or a discount that expires tonight.
- No written heat loss or roof assessment.
- A grant figure quoted as a certainty before eligibility is checked.
- Warranties described verbally but absent from the contract.
- A deposit request above 25% before any work starts.
- Anyone offering to handle your tax credit or rebate for you personally.
Check the warranty chain
You need three separate things: a product warranty from the manufacturer, a workmanship warranty from the installer, and confirmation that the product warranty is transferable if you sell the house. Ask for all three in writing, with durations.
Compare like for like
Two quotes are only comparable if they cover the same scope. Build a simple table of the model, the capacity, what is included, the grant applied and the net price — then compare. If one quote cannot be broken down that way, that is your answer.
Use this directory to shortlist two or three verified installers and request quotes for the same specification: heat pumps, solar, batteries and EV chargers — or start from a country hub.
Frequently asked questions
Is the cheapest quote ever the right choice?
Sometimes, but only when the scope, the equipment and the warranty match the others. A low price with an undefined scope is not a low price.
How many quotes should I get?
Three is the useful number. Two cannot reveal an outlier and four mostly repeats information.
What if something goes wrong after installation?
Start with the installer's written complaints procedure, then the accreditation body, which can investigate certified members. Keep your commissioning documents — they are what proves the system was installed to standard.