Your solar inverter is most likely shutting down due to grid voltage or frequency going outside acceptable limits, overheating, or a DC input fault from your panels. Start by checking the inverter display or app for an error code, and ensure ventilation around the unit is clear. If shutdowns are frequent, persistent, or accompanied by burning smells, contact a Part P registered electrician or MCS-accredited solar installer immediately. Do not attempt to open the inverter yourself.
🏠Homeowner view
A solar inverter shutting down repeatedly is frustrating, but it is usually trying to protect itself or your home. Understanding the most common reasons can help you decide whether this is something minor or a job for a professional.
The most common reason is a grid disturbance. UK inverters are set to disconnect automatically if the mains voltage or frequency drifts outside safe limits. This is a legal safety requirement, not a fault. If your neighbours are also having power issues, this may be the cause. It usually resolves on its own once the grid stabilises.
Overheating is another frequent culprit. Inverters generate heat during operation and need adequate airflow to stay cool. If yours is installed in a confined space, in direct sunlight, or near a boiler, it may be shutting down to prevent damage. Check that nothing is blocking the vents and that the area around the unit is reasonably cool.
Your solar panels themselves could be the problem. Shading from a new structure, bird droppings, or damaged cabling between the panels and inverter can cause the DC input to drop below the level the inverter needs to run. Have a look at the panels from ground level if it is safe to do so, but do not go onto the roof yourself.
A software or firmware issue can also cause shutdowns. Many modern inverters can be updated remotely through their app or web portal. Check whether an update is available from your manufacturer.
Error codes are your friend. Write down any code shown on the display or in the app and search for it on your inverter manufacturer's website. Common manufacturers in the UK include SolarEdge, SMA, Growatt, Solis, and Fronius, and each publishes fault code guides.
When to call a professional:
If shutdowns happen multiple times a day.
If you see error codes relating to insulation, earth fault, or isolation failure.
If there is a burning smell, discolouration, or visible damage.
If the inverter is completely dead and will not restart.
Always use an MCS-accredited installer or Part P registered electrician for any solar system work.