E07
Walli Contactor Weld / Stuck Relay Detection

Walli charger displays E07 and refuses to start; app shows 'Contactor weld detection' or 'Relay stuck'.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Welded contacts in Walli main contactor, Mechanical failure of contactor return spring, Faulty contactor drive circuit on Walli control board, Excessive inrush current from previous fault event

How to Fix / Troubleshooting

Safety first: A welded contactor can leave the output live even when the charger indicates off. Treat the cable as energized until verified otherwise.

Steps:

  • Turn off upstream breaker and verify the charger is fully de‑energized.
  • Open the Walli housing: Locate the main power contactor/relay module.
  • Visual and mechanical check: Inspect for burn marks or melted housing. Gently (with power off) try to move the contactor armature if accessible; it should move freely. If it is stuck, the contactor is defective.
  • Electrical test (technician only): With the unit disconnected, measure continuity across the contactor output terminals. If continuity is present when the coil is not energized, the contacts are welded.
  • Replace the contactor: Install a Walli‑approved replacement contactor or power module. Ensure all lugs are torqued to specification.
  • If a new contactor still triggers E07: The contactor monitoring circuit on the Walli main control board may be faulty and require board replacement.
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Repair Difficulty

Professional Required 5/5

Required Part

Walli power contactor
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