Just had solar fitted? What to check before you say "I'm happy"

The scaffolding is coming down, the installer is packing up, and they ask: "Are you happy with everything?"

Most people say yes, because they don't know what else to say. You've never had solar fitted before, so how would you know whether it's been done properly?

This checklist is for that moment. It covers what to check, what paperwork you should have, and what to ask before you sign anything off or pay the final balance. You don't need to be an electrician to use it.

The most important tip

Don't pay the final balance until you've worked through this list, or at least the "before the installer leaves" section. Once you've paid in full, it's much harder to get small problems put right.

It's completely reasonable to say: "Thanks. I'd like to go through a few checks before I sign off." A good installer will expect it.

Before the installer leaves

1. Ask them to show you round the system

Ask to see each part and have it explained in plain English:

• The panels: how many, and do they match your quote?
• The inverter (the box that converts solar power for your home): where it is, and what the lights or screen mean.
• The battery, if you have one: where it is and how it's set up.
• The isolator switches: where they are and when you'd use them. These switch the system off safely, for example if there's a fault.
• The generation meter, if fitted: what it records.

Check: do the brands and number of panels, inverter and battery match what's on your quote and contract?

2. Get the app set up and working

Ask the installer to set up the monitoring app on your phone, with you, before they leave.

Ask them to show you: how much your panels are making right now, how much you've used, and how much you've sent back to the grid.

Ask: "What would a normal day look like in summer and in winter?" Write down the rough figures. That way you'll know if something goes wrong later.

3. Look at the outside of the house

You can do most of this from the ground, or with the installer's photos:

• Ask for photos of the roof taken after fitting, especially around the edges of the panels.
• Look for cracked, slipped or missing tiles, and broken bits on the ground or in the gutters.
• Check cables running down the outside of the house are neatly fixed and protected, not loose or hanging.
• Check where cables come into the house, for example through a wall or the roof, and that the hole is sealed.
• Bird protection: if you asked for mesh to stop pigeons nesting under the panels, check it's been fitted.
• Check the garden and driveway for damage from the scaffolding.

4. Look inside

• The loft (if cables run through it): are cables neatly fixed? Any daylight showing through where there shouldn't be? Any insulation left disturbed?
• Around the inverter and battery: are they securely fixed, labelled and clear of clutter?
• Your fuse box (consumer unit): is there a new labelled switch for the solar? Are there warning labels saying the property has solar, which electricians need to know?
• Mess: has everything been cleaned up?

5. Check your meter

Ask the installer to show you which reading on your meter records electricity sent back to the grid.

Ask: "Will my smart meter record what I send back?" If you don't have a working smart meter, you won't be paid for spare electricity. (See our guide: Solar and smart meters: which meters work, and how to fix the ones that don't.)

The paperwork you should get

Ask for these before you pay in full, or at least confirm when you'll receive each one. Some arrive by post or email a few weeks later.

Tip: take photos of everything and keep it all in one folder, paper or digital. You'll need it if you switch supplier, claim on a warranty or sell your home.

Questions to ask before you sign off

Copy these into your phone before installation day:

• Does everything fitted match my quote: number of panels, brands and battery size?
• Can you set up the app with me and show me what normal looks like?
• Where are the isolator switches, and when would I use them?
• Can I see photos of the roof after fitting?
• Were any tiles cracked or replaced?
• Is my system G98 or G99, and has the network operator been notified or approved it?
• When will I get my MCS certificate and building regulations certificate?
• Do I have an insurance-backed guarantee, and who provides it?
• Will my meter record what I send back to the grid?
• Who do I contact if something goes wrong, and how quickly will you come out?

In the first few weeks

• Check the app on a few sunny days. Is your system making roughly what the installer said it would?
• Check your meter is recording what you send back, and that your supplier can see it.
• Apply for payments for spare electricity as soon as you have your MCS certificate. (See our guide: Solar export tariffs explained.)
• Tell your home insurer that you've had solar fitted.
• Look at the roof again after heavy rain or wind, from the ground. Any new slipped tiles or damp patches inside?

If you spot a problem, contact your installer in writing straight away. If they won't put it right, you can complain to the consumer code they belong to. It'll be named on your contract.

Would you like someone independent to check it for you?

We're thinking about offering an independent check of new solar installations in the North West, carried out by a qualified, independent electrician. It would include:

• a check of the panels, inverter, battery, wiring and labelling
• a roof check for cracked or slipped tiles, using photos or a drone
• a check that you have all the right paperwork
• setting up your app and showing you how to use it, including what "normal" looks like

Prices would start from about £149. Nothing to pay now. We'll only email you about this service, and you can ask us to remove your details at any time.