The Most Common Plug-In Solar Install Mistakes This Bank Holiday Weekend

Plug-in solar became legal in the UK on 27 August 2026, and the timing was no accident — four days later, England, Wales and Northern Ireland get the August bank holiday. If you bought a kit this week and are planning to fit it over the long weekend, you are one of many thousands of first-time UK "plug-in microgenerator" owners doing exactly the same thing right now.

Most installs go fine. A compliant 800VA kit really is a one-to-two-hour job with a screwdriver — see the full install walkthrough if you have not started yet. But a handful of avoidable mistakes are showing up repeatedly in the first 72 hours after people switch on, and most of them trace back to rushing the last 10% of the job rather than the panel-mounting itself. Here is what to check before, during and after you plug in.

Mistake 1: Using the wrong socket

Not every 13A socket in a UK home is a good candidate for an 800VA microgenerator. Kitchen ring mains shared with high-draw appliances, sockets on a spur already carrying an extension lead, and outdoor sockets without their own RCD protection are all places people are plugging in without checking first. The unit itself is designed to be forgiving, but a socket that is already near its limit, or that lacks RCD protection, is where problems start. Read which socket to use before you commit to a spot — it takes five minutes and saves a return trip to move the whole kit.

Mistake 2: Reaching for an extension lead

This is the single most common rule violation this weekend, and it is understandable — the nearest socket to where the panel naturally sits is very often not the nearest socket that is convenient. But the ban on extension leads between the inverter and the wall is not a suggestion; it is written into the interim product specification, and it exists because the fault-current and thermal assumptions behind the 5A fuse only hold for a direct plug-to-socket connection. If your panel position and your socket do not line up, move the panel, run a proper outdoor-rated mounting position closer to the wall, or get an electrician to add a new outdoor socket — do not bridge the gap with a lead. Full detail on why in the no extension lead rule explainer.

Mistake 3: Not checking the fuse rating before switching on

The plug on a compliant kit ships with a 5A fuse, not the 13A fuse most UK plugs default to. A small number of kits arrive with a spare 13A fuse loose in the box for an unrelated accessory, and in the rush of a bank holiday build it is easy to grab the wrong one if you have swapped plugs for any reason. Always check the fuse rating stamped on the fuse itself before you switch on for the first time. If yours trips or blows shortly after energising, do not just swap in a higher-rated fuse to make the tripping stop — read what a blown 5A fuse actually means first, because it is very often telling you something real about the circuit.

Mistake 4: Forgetting the RCD is doing its job, not failing

If your microinverter trips the RCD in the first few minutes of a sunny afternoon, the instinctive reaction is to assume the kit is faulty. Sometimes it is — but far more often on a first install it is a nuisance trip caused by earth leakage that is well within normal limits for a Type A RCD but happens to coincide with another appliance switching on nearby. Isolate the circuit, check what else was running at the time, and work through the RCD tripping guide before assuming you have a dud unit. Repeated trips on an otherwise quiet circuit are the one pattern worth escalating to the retailer.

Mistake 5: Skipping — or delaying — the G98 notification

Because there is no installer on site to remind you, G98 notification is the step people are most likely to forget over a long weekend when DNO contact-centre attention is elsewhere. You have 28 days from energising to submit it, which feels like plenty of time, but the honest advice is to do it before you even open the box: it takes about ten minutes online, does not require the kit to be running yet, and removes one more thing from your bank holiday to-do list. The G98 notification step-by-step guide covers exactly what your DNO will ask for.

Mistake 6: Expecting full output on day one

Cloud cover, a panel angle that has not yet been fine-tuned, and a monitoring app that takes a few hours to sync all combine to make day-one output look disappointing even on a perfectly healthy system. Give it 48–72 hours and a couple of clear spells before you judge performance. If the app itself will not show any generation at all rather than just lower-than-hoped numbers, that is a different problem — see monitoring app not working or, if it is your smart meter rather than the manufacturer app that is blank, smart meter not showing solar generation.

Mistake 7: Mounting on a circuit with old or unknown wiring

Some of the UK housing stock going into this weekend's install rush includes homes with wiring that predates modern consumer units. If your home does not have RCD protection at the consumer unit, or you are not sure whether it does, that is worth resolving before rather than after you plug in — not because the microgenerator itself is dangerous, but because it is designed on the assumption of a modern protective setup. The old wiring guide explains what to check and when it is worth a fifteen-minute call to an electrician first.

If something still is not right by Tuesday

Most nuisance issues resolve themselves once the initial rush settles: a socket gets moved, a fuse gets swapped for the correct rating, or the app finishes syncing. If you are still seeing a genuine fault — repeated RCD trips on an otherwise stable circuit, zero output in clear conditions, or physical damage to the plug or cable — stop using the unit and contact the retailer rather than working around it. Under UK consumer law you are entitled to a repair, replacement or refund for a kit that is not fit for purpose, and trying to force a workaround yourself can complicate that claim. For the full checklist before you buy in the first place, see the buying checklist; if you are further along and want the day-by-day plan for your first week of ownership, your first week with plug-in solar covers what normal actually looks like.

Can I use an extension lead just to get through installation weekend?

No. The no-extension-lead rule applies from the moment the kit is energised, not just as a long-term condition — plugging in through a lead, even temporarily, takes the installation outside the interim product specification. Reposition the panel or the socket instead.

My plug-in solar kit tripped the RCD on first use — is it faulty?

Not necessarily. A single trip in the first few minutes is often a nuisance trip rather than a fault, especially if another appliance switched on around the same time. Isolate, retest on a quiet circuit, and only treat it as a fault if the trips repeat consistently — see the RCD tripping guide linked above for the full diagnostic steps.

Do I need an electrician to install a plug-in solar kit this weekend?

No — a compliant kit is designed for DIY installation by design, that is the entire point of the plug-in microgenerator category. The exception is if your consumer unit lacks modern RCD protection or your wiring is otherwise in doubt, in which case a short electrician check before you plug in is worth the cost.