My Solis Inverter Is Blank or Won't Turn On: Safe Checks Before Calling Your Installer
A blank screen does not always mean failure. On the S6-EH1P(3-8)K-L-PLUS family, the screen sleeps after a few idle minutes and should return after a front-panel button press. Solis defines a genuinely non-starting inverter as a blank display, no indicator lights and no generation.
Scope and safety The safe observations in this guide can help any homeowner describe a blank Solis inverter. The detailed screen and indicator meanings apply only to the S6-EH1P(3-8)K-L-PLUS European family, including the Solarboss S6-EH1P5K-L-PLUS. RHI, S5 and other S6 families can use different displays, menus and power arrangements. Do not apply this S6 procedure to them. Do not remove covers, touch PV connectors, take voltage/current measurements, work on breakers or follow an online shutdown/restart sequence. Those tasks require a qualified installer.
The direct answer
For an S6-EH1P(3-8)K-L-PLUS:
- Look at the screen and the labelled POWER, OPERATION and ALARM indicators without touching the equipment.
- If the screen alone is blank but an indicator is lit, press one front-panel button once. The official manual says any of ESC, UP, DOWN or ENTER restores the screen after idle sleep.
- If the screen wakes, read the status but do not enter or change settings.
- If the display and every indicator remain off, or an alarm indicator is active, record the evidence and contact the installer.
Do not test PV voltage or polarity yourself. Although Solis's technical troubleshooting process asks for electrical measurements, those are hazardous diagnostic tasks, not homeowner checks.
First decide what "blank" means
Separate these commonly confused situations before phoning support:
- Screen asleep: the display is dark, but one or more status indicators are visible. On the specified S6 family, one button press should restore the display.
- Screen fault or interface issue: indicators suggest that the inverter has power, but the display does not return after one press.
- Inverter stopped: power may be detected, but the OPERATION indicator is off.
- True no-start symptom: the display is blank, all indicators are off and there is no evidence of generation.
- Monitoring-only problem: SolisCloud is offline or stale, but the inverter's external display or indicators remain active.
"The app is offline" is not enough evidence that the inverter has no power.
Safe checks for the S6-EH1P(3-8)K-L-PLUS
1. Try the screen wake-up once
The official S6 manual says its screen turns off after a few minutes of inactivity. Press any one of the four front-panel buttons once to restore it. Use a single, ordinary press; do not hold buttons, enter menus or change settings.
If the screen returns, photograph the home/status page and note the time. The original blank screen was probably the normal idle behaviour described in the manual. If it remains blank, move to the indicators.
2. Read the three inverter indicators
On this S6 family, the manual defines:
- POWER on: the inverter can detect a power supply.
- POWER off: no power is detected by the inverter.
- OPERATION on: the inverter is fully operational.
- OPERATION flashing: the inverter is initialising.
- OPERATION off: the inverter has stopped operating.
- ALARM on: the inverter has detected an emergency fault.
- ALARM flashing: the inverter has detected a fault or warning.
- ALARM off: the inverter has not detected a fault.
Write down the labelled light and whether it is on, off or flashing. A ten-second video is better than relying on memory. Do not interpret these states using a manual from a different Solis family.
3. Check time, daylight and recent history
Record whether the problem is happening in daylight, after dark or during a grid outage. Time of day helps the installer decide what power sources would normally be available. The S6-EH1P(3-8)K-L-PLUS manual says that family can be powered from PV, battery or grid, but the actual commissioned arrangement varies by installation.
Also record:
- when the inverter last appeared normal;
- whether work was recently done on the house, meter, consumer unit or solar system;
- whether the grid supply is present elsewhere in the home;
- whether SolisCloud has a recent timestamp;
- whether the system is newly installed or has operated normally for months or years.
Do not assume an early Irish winter morning is a fault, and do not wait for stronger sun if an alarm, burning smell, unusual sound or repeated protective-device trip is present.
4. Look, but do not operate
From a safe position, check only externally visible information:
- Is the inverter casing intact and dry?
- Are any normal external switches visibly in a different position from the labelled handover state?
- Does a consumer-unit device clearly labelled for solar appear tripped?
- Is an external battery or communications unit showing an alarm?
This is a visual record, not permission to switch or reset equipment. Do not repeatedly reset a tripped breaker, turn a DC isolator under load, open a cabinet or touch a PV plug. Give the observations to the installer.
What the installer may need to check
Solis's official "inverter won't turn on" article asks for PV open-circuit voltage, polarity, DC current and voltage-to-earth tests. The S6 manual's commissioning sequence also contains AC and DC measurements. These checks involve potentially lethal voltages and qualified procedures.
That explains why a useful homeowner report matters: it helps the installer arrive prepared, but it does not make electrical testing safe to do yourself. Do not send photographs of yourself holding probes on PV connectors. Ask the installer to perform and document the required measurements.
For a new installation, the installer may need to confirm that the exact model's startup requirements and PV polarity are correct. For a system that previously operated, the installer may need to assess the PV strings, supply, protection and inverter condition. The action depends on the precise model and installation; this guide deliberately does not prescribe it.
Do not mix RHI, S5 and S6 instructions
"Solis inverter" is a brand description, not a service procedure. The current Solarboss product linked here is SOL-S6-EH1P5K-L-PLUS-10Y, within the S6-EH1P L-PLUS family covered by the archived manual used for this guide.
An RHI-5K-48ES-5G, an S5 hybrid and a different S6 model can have a different interface and sequence. If the nameplate does not begin with the family stated in the scope box, use the official Solis download centre to locate the exact manual, or send the full model to the installer. Do not choose a manual because the power rating happens to be 5 kW.
Stop and call your installer immediately when
Keep clear of the equipment and contact a qualified installer if:
- POWER, OPERATION and ALARM indicators all remain off in conditions where the system would normally be available;
- ALARM is on or flashing;
- the consumer-unit protective device trips again or will not remain on;
- the inverter or adjacent equipment is wet, damaged, unusually hot, noisy or smells burnt;
- there was recent electrical, roof, meter or solar work;
- a cover, connector, cable, isolator or breaker would have to be accessed;
- the screen stays blank even though the POWER or OPERATION indicator is on;
- the system is newly commissioned and has never operated correctly;
- the exact model cannot be confirmed.
The S6 manual warns that the product contains lethal voltages, has no user-serviceable parts inside and should be serviced by qualified personnel.
Information to collect for support
The S6 manual asks users to have core system and fault information ready. Send:
- full inverter model and serial number;
- installer or supplying dealer, if known;
- installation date;
- date and time the blank-screen symptom was noticed;
- whether the issue is screen-only or screen plus all indicators;
- POWER, OPERATION and ALARM states;
- whether one button press restored the S6 screen;
- exact message or alarm shown, if the display returns;
- last SolisCloud update time and a screenshot;
- whether the grid supply is present in the home;
- whether the system is new or previously worked normally;
- a clear photo of the closed inverter and a short indicator video;
- basic PV array description, such as number of panels and strings, if available from the handover pack;
- your contact details.
Never remove a cover or expose a serial label that is only accessible inside the unit.
Frequently asked questions
Why is my S6 screen blank when the lights are still on?
The S6-EH1P(3-8)K-L-PLUS manual says the screen automatically turns off after a few idle minutes. Press one front-panel button once to restore it.
Does a blank SolisCloud page mean the inverter is off?
No. SolisCloud depends on the datalogger and home network. Check the inverter's external display and indicators separately.
Can I reset the inverter myself?
This guide does not recommend a homeowner reset. Solis technical procedures involve AC, DC and battery isolation and electrical measurements. Ask the installer to use the sequence for your exact model.
Can I test the panel voltage with a multimeter?
No. Solis may request those readings during technical diagnosis, but PV strings can present dangerous DC voltage. A qualified installer should perform the tests.
Which Solarboss product does the S6 detail apply to?
It applies to the family containing the Solarboss S6 5 kW Plus low-voltage hybrid inverter, model SOL-S6-EH1P5K-L-PLUS-10Y. Confirm the nameplate before using the family-specific detail.