Solar Panel Repair Cost Calculator
Most solar faults are the inverter, not the panels. Pick the symptom and this prices the likely repair, including whether roof access is needed.
Open the calculator →Price your solar fault in 30 seconds
4 steps. Covers diagnosis, the repair itself, roof access where the panels have to come off, and region.
How this calculator works
The calculator prices by symptom rather than by part, because that is all you can know before someone looks. If generation has stopped completely, the inverter is the overwhelming favourite — panels rarely fail outright, and a string inverter reaching 10–15 years is at the end of its expected life.
Access is priced separately because it frequently costs more than the repair. Replacing one £375 panel on a two-storey roof can carry £800 of scaffolding. If you need the roof opened up anyway, it is worth asking what else should be done in the same visit — bird proofing in particular, since retrofitting it later means paying for the scaffold twice. It is also worth having the installer read the fault code and check the monitoring history before quoting a part, because an inverter that trips intermittently on a grid-voltage fault looks identical to a failed one from the ground and needs a very different, usually cheaper, fix. One warranty point that saves real money: panels usually carry a 10–25 year product warranty and inverters around 5–12 years, so before paying for a replacement dig out the original paperwork and check what is still covered — a failed inverter inside its term is the manufacturer’s cost, not yours. If the array is old enough that repairs are becoming a habit, our solar panel cost calculator shows what a fresh system runs to, and the solar panel grants guide covers the help available towards one.
Solar repair costs by job (2026)
| Repair | Typical 2026 cost | Notes |
|---|---|---|
| Diagnostic call-out | £80–£150 | Often credited against the repair |
| System health check | £100–£250 | Full string and inverter test |
| String inverter replacement | £800–£2,000 | The most common major failure |
| Micro-inverter / optimiser | £150–£400 each | Priced per unit |
| Single panel replacement | £250–£500 | Matching an older panel can be the issue |
| Isolator or wiring fault | £150–£450 | Often water ingress at the roof entry |
| Bird / pigeon proofing | £400–£900 | Clearance plus mesh to the whole array |
| Panel removal and refit | £500–£1,500 | Where roof work is needed underneath |
| Monitoring reconnection | £80–£200 | Gateway or comms fault |
Figures match our solar repair cost guide. Scaffolding is extra where the roof must be accessed and is frequently the largest line on an otherwise small job.
Solar repair calculator FAQs
The inverter, in most cases. Panels are solid-state and rarely fail outright, whereas inverters carry fans, capacitors and electronics and typically last 10–15 years. Check the inverter display or your monitoring app for a fault code before booking anything. A quick check first can save a call-out entirely: if the isolator has tripped or the display is simply blank after a power cut, resetting it in the right order often brings the system straight back, and a reputable installer will talk you through that before sending anyone out.
If the unit is past ten years and the repair is more than about £400, replace it. Parts availability for older inverters is poor, and you will likely be paying again within a couple of years. A replacement also gives you the option of a hybrid unit if a battery is on the horizon.
Because it is priced by erection and hire, not by the size of the job underneath it. A one-panel swap and a full array clean carry much the same access cost, which is why it is worth bundling anything roof-level into a single visit.
Possibly. Panels commonly carry 12–25 year product warranties and inverters 5–12 years, but they cover the part and rarely the labour or access. Find your MCS certificate — it names the installer and the commissioning date, which is where any claim starts. If you have lost the paperwork, the installer or the MCS database can usually recover the certificate from your address, so it is worth chasing before you pay out of pocket for something a live warranty would have covered.
Related cost guides
- Solar repair cost guide — every fault priced in detail
- Solar panel cleaning — when output loss is dirt, not a fault
- Solar battery calculator — if you are replacing the inverter anyway
- Solar panel costs — what a full replacement system costs
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