- Solar and energy
- Solar inverter
18x75
SolarEdge 18x75 on solar inverter: Overtemp high temperature
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
Code 18x75 (error 117 on firmware 3.18xx and below, Overtemp) means the SolarEdge inverter temperature is too high. Check from the outside that proper clearances around the inverter are kept and that the heat-sink fins are clean and unobstructed.
Safety first
Stop and check this first
- The heat-sink fins can be hot when code 18x75 (Overtemp) is active: do not touch the heat sink with bare hands or poke metal tools or water into the fins.
Safe checks you can perform
- Confirm code 18x75 or the high-temperature LED indication
- Check that nothing blocks the clearances around the inverter
- Inspect the heat-sink fins from outside for dust or debris
Leave these tasks to a qualified professional
- Do not attempt this professional task: Clearance verification and heat-sink fin cleaning
- Do not attempt this professional task: Error history review and escalation to SolarEdge Support
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Clearance verification and heat-sink fin cleaning
What they doThe installer verifies that the inverter clearances meet SolarEdge guidelines for heat dissipation and cleans any obstructions from the heat-sink fins.
They must show youthe measured clearances around the inverter and the condition of the heat-sink fins before and after cleaning.
In writingthe clearance measurements, the cleaning performed and any recommendation on shading or ventilation.
Error history review and escalation to SolarEdge Support
What they doIf 18x75 persists with clean fins and proper clearances, the technician checks the Errors tab or SetApp for related codes such as 18x85 (133, Temp Sensor fault) and contacts SolarEdge Support.
They must show youthe error log in the monitoring platform or SetApp after testing the inverter.
In writingthe recorded error codes, operating temperature readings and any SolarEdge Support case reference.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Confirm code 18x75 or the high-temperature LED indication
- Who:
- you, checking the display, monitoring portal or LEDs without opening any enclosure.
- How:
- check whether 18x75 (117, Overtemp) appears on the screen or in the monitoring platform Errors tab; on screenless inverters, move the ON/OFF/P switch to P for 2 seconds and release it: green blinking with red and blue off indicates High temperature.
- Result that matters:
- making sure the stop or derating is due to high temperature rather than a different fault such as 18x85 (Temp Sensor fault).
- If 18x75 (Overtemp) is listed or the green LED blinks after releasing P:
- proceed with the external airflow checks below.
- If 18x85 (error 133, Temp Sensor fault) appears instead:
- SolarEdge says to contact support because it points to a broken or unconnected temperature sensor.
- Evidence to keep:
- a photo of the 18x75 message or a screenshot of the Errors tab with the timestamp.
Evidence: Appendix A: Errors and Troubleshooting (Single Phase Inverter with HD-Wave Technology Installation Guide, MAN-01-250-1.2) · Installation Guide: Three Phase Inverters with Synergy Technology (PN: SEXXK-XXXXIXXXX, Version 1.2)
Check that nothing blocks the clearances around the inverter
- Who:
- you, inspecting the area around the inverter from the outside.
- How:
- look for boxes, shelves, covers or stored items placed too close to the inverter that reduce its mounting clearances, and note whether direct midday sunlight hits the enclosure.
- Result that matters:
- spotting external obstructions that trap heat around the inverter.
- If items are blocking the space around the unit:
- move them away to restore clearance and see whether the error clears once the unit cools.
- If clearances are already open but the room is hot or in full sun:
- note those conditions for your installer.
- Evidence to keep:
- a wide photo showing the inverter mounting spot and the surrounding clearance.
Evidence: Appendix A: Errors and Troubleshooting (Single Phase Inverter with HD-Wave Technology Installation Guide, MAN-01-250-1.2) · Installation Guide: Three Phase Inverters with Synergy Technology (PN: SEXXK-XXXXIXXXX, Version 1.2)
Inspect the heat-sink fins from outside for dust or debris
- Who:
- you, looking from the outside without opening the inverter or touching cables.
- How:
- look at the inverter heat-sink fins to see whether dust, leaves, cobwebs or debris are blocking airflow along the fins.
- Result that matters:
- knowing whether the heat-sink fins need cleaning as listed in the SolarEdge table for 18x75.
- If debris is visible on the fins or 18x75 keeps returning:
- call your installer to clean the heat sink safely and verify clearances.
- If the fins look clean and 18x75 persists even in cool weather:
- ask your installer to inspect the unit and contact SolarEdge Support.
- Evidence to keep:
- a close-up exterior photo of the heat-sink fins and a note of the ambient temperature.
Evidence: Appendix A: Errors and Troubleshooting (Single Phase Inverter with HD-Wave Technology Installation Guide, MAN-01-250-1.2)
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Solar and energy
- Brand
- SolarEdge
- Product type
- Solar inverter
Known code variants
- sobretemperatura inversor SolarEdge
- SolarEdge 18x75
- SolarEdge error 117
- SolarEdge error 18x75
- SolarEdge inverter high temperature
- SolarEdge Overtemp
- SolarEdge temperatura demasiado alta
- SolarEdge temperature too high
What it means
In Appendix A of the SolarEdge installation guide (MAN-01-250-1.2, page 58), code 18x75 (error 117 on CPU v3.18xx and below) carries the message 'Overtemp' and means 'Temperature too high'. The Three Phase Inverters with Synergy Technology installation guide (Version 1.2, pages 30 and 65) adds that high temperature is shown on the inverter LEDs by a blinking green LED and recommends mounting the inverter out of direct sunlight with proper clearance for heat dissipation. Seeing 18x75 alone does not prove that the inverter or its temperature sensor is defective.
Warnings and stop conditions
- Mediumsource verified
The heat-sink fins can be hot when code 18x75 (Overtemp) is active: do not touch the heat sink with bare hands or poke metal tools or water into the fins.
Evidence: Appendix A: Errors and Troubleshooting (Single Phase Inverter with HD-Wave Technology Installation Guide, MAN-01-250-1.2)
Symptoms and causes
Probable causes · in order
- Heat-sink fins dirty or obstructedCommon
The SolarEdge troubleshooting table for 18x75 (117) instructs making sure that the heat-sink fins are clean and unobstructed.
Evidence: Appendix A: Errors and Troubleshooting (Single Phase Inverter with HD-Wave Technology Installation Guide, MAN-01-250-1.2)
- Insufficient mounting clearances or direct sunlightPossible
SolarEdge specifies verifying proper inverter clearances for heat dissipation and recommends mounting the unit in a location protected from direct sunlight.
Evidence: Appendix A: Errors and Troubleshooting (Single Phase Inverter with HD-Wave Technology Installation Guide, MAN-01-250-1.2) · Installation Guide: Three Phase Inverters with Synergy Technology (PN: SEXXK-XXXXIXXXX, Version 1.2)
Virtual technician
Does 18x75 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
SolarEdge Technologies · manual
- 2
Installation Guide: Three Phase Inverters with Synergy Technology (PN: SEXXK-XXXXIXXXX, Version 1.2)
SolarEdge Technologies · 2021 · manual
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