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Error codes
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Error codes
HVAC in the field
Click the search box to display the codes. Filter by brand or type the code shown on the display.
Click the search box and choose a code to see the diagnosis.
E4
BRAND
Title
Severity
Applies to
Violet chips are models confirmed in the manual; gray ones are the series/family where it applies.
What it means
Probable causes
Electrical hazard. Some steps require measurements with live voltage. Trained personnel only, with proper PPE and tools. When in doubt, cut power at the panel.
Suggested inspection steps
Important: error codes vary by equipment model and series. This information is for guidance only. Always check the service manual for the specific model before working on the unit.
Logging this fault?
Save the diagnosis to the equipment log and send it to your customer with Lissi.
Database updated to Junio 2026 · Reference information in progress