- Networks
- Garage door openers
E4
Somfy E4 garage door motor: safety self-test failure
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
High
Quick answer
Code E4 on a Somfy Dexxo Pro 800 RTS or 1000 RTS garage door motor means the safety device self-test failed, preventing any door movement. Gently clean the photocell lenses and check for visible misalignment without bridging terminals; contact an installer if E4 persists.
Safety first
Stop and check this first
- Never bridge safety terminals or set P2=0 to force door operation when E4 is displayed, and keep away from door springs and counterbalance cables.
- Disconnect both the mains power supply and any backup battery before performing any technical work on safety peripherals or wiring.
Safe checks you can perform
- Confirm E4 appears when a movement command is sent
- Clean the external optics and check visible alignment
- Note any recent setup or accessory changes for the technician
Leave these tasks to a qualified professional
- Do not attempt this professional task: Match parameter P2 to the installed safety peripheral
- Do not attempt this professional task: Inspect safety test wiring and cell alignment with power off
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.
Match parameter P2 to the installed safety peripheral
What they doThe technician checks whether the installed safety device uses self-testing (P2=1 for self-test TX/RX cells, reflex cell, or sensor bar) or standard wiring without self-test (P2=2), configuring P2 properly without disabling protection.
They must show youthe installed safety device type, its wiring diagram in the manual, and the matching P2 setting.
In writingsafety accessory model, verified parameter P2 value, and self-test result after configuration.
Inspect safety test wiring and cell alignment with power off
What they doAfter cutting the 230 V mains power and disconnecting any backup battery, the installer checks the safety input and test output wiring, aligns the photoelectric cells, and runs a complete operating test.
They must show youthe checked safety terminal connections, aligned cells, and a movement cycle free of code E4.
In writingsafety input and test output wiring findings, alignment performed, and confirmed return to code C1.
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 E4 appears when a movement command is sent
- Who:
- you, watching the 2-character LCD on the Dexxo Pro motor head from a safe spot.
- How:
- press the remote control and check whether the display briefly shows Ca for the self-test and then stops with E4 while refusing door movement.
- Result that matters:
- confirm that the opener is stopping because of the safety self-test failure E4.
- If E4 appears and the door remains stationary:
- continue with the external optical inspection.
- If another code such as pedestrian door code C9 appears:
- follow the guidance for that specific status.
- Evidence to keep:
- sequence of 2-character codes seen on the motor display when requesting movement.
Evidence: Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
Clean the external optics and check visible alignment
- Who:
- you, with the door stationary and without opening covers or touching any wiring.
- How:
- remove any object in the threshold, gently wipe the photoelectric lenses or reflex reflector with a soft cloth without high-pressure water, and check whether the units face each other.
- Result that matters:
- clear external optical interference that can make the automatic pre-movement test fail.
- If the self-test passes after cleaning and E4 clears:
- observe a full open and close test cycle.
- If E4 continues to block door travel:
- call a qualified technician without bypassing any safety device.
- Evidence to keep:
- condition of the lenses or sensor bar and whether E4 remained after cleaning.
Evidence: Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
Note any recent setup or accessory changes for the technician
- Who:
- you, reviewing recent maintenance or parameter changes on the garage door installation.
- How:
- write down whether E4 started after menu adjustments, peripheral work, or a power outage, without pressing the SET button on the motor head.
- Result that matters:
- help the installer determine whether parameter P2 or the test wiring needs correction.
- If setup or accessory work preceded E4:
- inform the installer before they inspect parameter P2.
- If E4 appeared during normal use with no changes:
- ask the technician to inspect test wiring and alignment.
- Evidence to keep:
- when E4 first appeared and any recent work on the opener or safety accessories.
Evidence: Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
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
- Networks
- Brand
- Somfy
- Product type
- Garage door openers
Known code variants
- 4 flashes
- 4 parpadeos
- Aviso E4 de eje de la devanadora
- Bobbin winder shaft E4 warning
- Brother FS60x E4
- cabezal tado E4
- Candy lavadora E04
- Candy lavadora E4
- Candy washer 4 flashes
- Candy washer E4
- Candy washer too much foam E4
- Candy washing machine E04
- E 04
- E 4
- E-04
- E-4
- E04
- E4
- E4 message on the LCD
- Electrolux dishwasher E4
- Electrolux dishwasher error E4
- Electrolux EHFE14T6MSBUS E4
- Electrolux LL14X E4
- Error 04
- Error 4
- Error E4
- error E4 lavavajillas Electrolux
- error E4 tado calibración
- Fallo auto test dispositivo de seguridad
- Hoover E04
- Hoover E4
- Hoover washing machine E04
- Hoover washing machine E4
- lavadora Candy 4 parpadeos
- lavadora Candy mucha espuma E4
- lavadora Hoover E04
- lavadora Hoover E4
- Mensaje E4 en la pantalla LCD
- Safety mechanism self test fault
- Somfy Dexxo Pro E4
- tado Basic seis rayas llave inglesa
- tado Basic six dashes spanner
- tado E4
- tado E4 calibration error
- tado radiator thermostat E4
- tado Smart Radiator Thermostat E4
- tado° E4
What it means
Somfy's installation manual for Dexxo Pro 800 RTS and Dexxo Pro 1000 RTS (5048550F) defines E4 as “Safety mechanism self test fault”. When parameter P2 is set to 1, the opener runs an automatic test (code Ca) on the photoelectric cells, reflex cell, or sensor bar before every movement and blocks travel if the test fails. Other Somfy models may differ. Code E4 alone does not prove a component is defective.
Warnings and stop conditions
- Highsource verified
Never bridge safety terminals or set P2=0 to force door operation when E4 is displayed, and keep away from door springs and counterbalance cables.
Evidence: Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
- Mediumsource verified
Disconnect both the mains power supply and any backup battery before performing any technical work on safety peripherals or wiring.
Evidence: Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
Symptoms and causes
Probable causes · in order
- Parameter P2 set to 1 with a non-self-testing peripheralCommon
Selecting P2=1 when standard photoelectric cells without a self-test connection are installed causes the pre-movement check to fail with E4.
Evidence: Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
- Optical misalignment or blocked beam during test CaPossible
Misaligned or obstructed photoelectric cells at the moment the opener runs automatic check Ca prevent a valid test response and trigger E4.
Evidence: Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
- Wiring fault on the safety input or safety test outputPossible
Loose, reversed, or damaged wiring between the motor head safety test output and the peripheral terminals produces self-test fault E4.
Evidence: Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
Virtual technician
Does E4 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
Somfy Dexxo Pro 800 RTS y 1000 RTS: Manual de instalacion (5048551F)
Somfy · 2026 · official_doc
- 2
Somfy Dexxo Pro 800 RTS and 1000 RTS: Installation Manual (5048550F)
Somfy · 2026 · official_doc
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