Troubleshooting
Solar troubleshooting, fault by fault
What you will see, why it happens, what you can safely check yourself and when to call us. Never open the DC side yourself: solar strings stay live whenever there is daylight.
Backup and load-shedding
- Why does an on-grid inverter stop during load-shedding?
- Hybrid inverter is running, but backup circuits have no power
- Load division: choosing which appliances run on solar backup
- Why do computers and routers restart during solar backup changeover?
- Why does solar backup stop when clouds pass?
- Why won’t a hybrid inverter restart after the battery runs flat?
- Why does an existing UPS behave strangely on solar backup?
- Why do appliances work on grid electricity but struggle on solar backup?
- Why do lights flicker only on battery backup?
- Can a hybrid inverter provide daytime backup without batteries?
Inverter faults
- Inverter trips on high or low grid voltage
- Overvoltage trips on sunny afternoons
- Isolation or ground fault after rain
- Inverter overheating and derating in summer
- Inverter display is blank with no lights
- How to read an inverter fault code
- Arc fault warnings and burnt MC4 connectors
- Faults that only appear after sunset
- Firmware glitches and false error codes
- Inverter fan noise, humming or vibration
- Voltage spikes when power returns after load-shedding
- Inverter trips when looms or large motors start
- Generator and changeover safety with solar
- Why do parallel hybrid inverters appear to share the load unevenly?
- Why does a PV overvoltage warning appear on cold mornings?
- What is the difference between a grid-frequency fault and a grid-voltage fault?
- What happens when the inverter loses communication with its meter or export controller?
- Why does the inverter report a relay self-check fault?
- What should be checked after an inverter firmware update?
Batteries
- Battery is connected but the inverter cannot see it
- Why “supports CAN or RS485” does not mean compatible
- Battery percentage jumps or drifts
- “BMS offline” alarms that come and go
- Why is battery backup shorter than the estimated duration?
- Why does the battery drain when the house or business appears switched off?
- Why does the system use grid electricity when the battery still has charge?
- Why can’t I run more appliances after adding another battery?
- Can I add a new lithium battery to an older battery bank?
- Why is some battery capacity missing after an expansion?
- What does a battery cell-imbalance alarm mean?
- Why does the battery breaker trip when the inverter starts?
- What should I do if a battery swells, leaks or gives off an unusual smell?
- How should a solar battery be stored and restarted after months without use?
- What does a cooling-system alarm on an industrial battery cabinet mean?
- What should staff do when an energy-storage cabinet gives a fire or gas alarm?
Battery charging
- Why are the solar panels generating but the battery is not charging?
- Why is the battery charging from the grid on a sunny day?
- Why is the battery charging more slowly than expected?
- Why does battery charging stop before reaching full?
- Why does the system export electricity before charging the battery?
- Why does battery charging pause when the battery room gets hot?
- Why is battery charging limited on cold mornings?
- Why does scheduled battery charging fail to start?
- Why does one parallel battery charge more slowly than the others?
- Why does the battery keep switching between charging and discharging during the day?
Panels and generation
- Dust, smog and monsoon losses
- Output lower than usual at midday
- Hot spots on solar panels
- PID: the slow, hidden power loss
- Normal degradation or a real fault?
- Solar panel junction box failures
- Why output drops in Lahore’s smog season
- White stains on panels after washing
- Cracked panels after a hailstorm
- Checking your panel structure before storm season
- Textile lint and industrial dust on Faisalabad rooftops
- Sawtooth shed roofs: shading and cleaning access
- Housekeeping around solar on textile rooftops
- Why do two solar inverters at the same property produce different amounts?
- Why do solar panels not always produce their nameplate wattage?
- Is a flat solar production curve normal clipping or a fault?
- Why does one PV string or inverter input show zero?
- Why did solar production fall after adding more panels?
- Why am I seeing little extra generation from bifacial panels?
- What are the dark lines or snail trails appearing on my panels?
- Why is a solar panel bubbling, peeling or turning yellow?
- What should I do about birds nesting beneath solar panels?
- Could handling or roof work have caused microcracks in my panels?
- How can a discontinued solar panel be replaced correctly?
- How should I check a contractor’s solar-panel cleaning method?
- Why did production change after a water tank, wall or nearby building was added?
Monitoring and billing
- Monitoring offline after a router change
- Exported units do not match the bill
- Waiting for a LESCO green meter after paying the demand notice
- Billed under net billing when you signed for net metering
- Why commercial files above 25 kW take longer at FESCO
- Factory solar: using it yourself versus exporting
- Why does the solar app show negative household consumption?
- Why do solar, battery, grid and load figures not add up in the app?
- Can missing solar history be recovered after an internet outage?
- Why does solar production appear at the wrong time or on the wrong date?
- Why does my inverter or logger say it is already registered?
- How can I recover access to my solar monitoring account?
- Can I change the installer linked to my solar monitoring account?
- Why does the app lag behind the inverter screen?
- Why did I receive no notification when my solar system developed a fault?
- Why are old or duplicate devices still visible in the solar app?
- Why is my electricity bill still high after installing solar?
- Why does the house import electricity while the sun is shining?
- What should I do if the electricity meter’s display goes blank?
- Which readings should I keep when the utility replaces my electricity meter?
- Why is my electricity bill based on an estimate when solar monitoring is available?
- How do arrears and adjustments affect the bill after solar installation?
- Why has my factory’s maximum-demand charge not fallen with solar generation?
- Why can a factory’s power factor become worse after solar installation?
- How should a landlord and tenant check a shared solar electricity statement?
- Why does a zero-export system occasionally show electricity going to the grid?
- Should I give a technician remote access to my solar system?
Wiring and electrical safety
- Why does the AC breaker trip when the inverter shows no fault?
- Why does the earth-leakage device trip only on solar backup?
- What should I do about buzzing, a burning smell or scorch marks at the electrical board?
- Why do taps, appliances or metalwork give an electric tingle?
- What should I do if solar cables are exposed or the conduit is cracked?
- What should I do if rodents have damaged solar wiring?
- Why is fitting a bigger breaker not a fix for repeated tripping?
- Can a long AC cable cause voltage problems or energy losses?
- What if my solar installation has no earthing test records?
- Can solar equipment be restarted after floodwater or roof water gets inside?
- What should be checked after a fire near a solar installation?
- Does an IP rating mean an inverter or battery can tolerate any outdoor condition?
- Why does switching off the main breaker not make the whole solar system safe?
Roof and structure
- What should happen if roof renovation disturbs the solar system?
- What should I do if my roof leaks after solar installation?
- Should solar structure base plates be fixed to tiles or the structural slab?
- What do cracks or crumbling concrete around solar supports mean?
- Can a solar structure block roof drainage or cause standing water?
- Why must roof access and maintenance space be planned around solar panels?
- Why does rust return after a solar structure has been repainted?
- Does a solar installation near Karachi’s coast need different corrosion checks?
- Can solar panels be installed on an old or apparently weak roof?
- Is it safe for solar panels to extend beyond a roof or support frame?
- What should be agreed before removing and reinstalling solar panels for roof repairs?
Warranty, records and service
- What should I record when a solar fault keeps coming back?
- What should be checked when buying or taking over a property with solar?
- What evidence helps an inverter warranty claim?
- What is the difference between a solar panel’s product and performance warranties?
- What should a solar repair or replacement quotation include?
- What if my solar installation’s handover documents are missing?
- What needs to be checked after replacing a solar inverter?
- How can I check inverter and battery identification before accepting delivery?
- Does a battery’s advertised cycle life tell me how long its warranty lasts?
- Who pays for a solar service visit when a component is under warranty?
- What should a completed solar repair report tell me?