Display shows A15; water heater indicates internal control fault or EEPROM error.
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.
Possible Causes
How to Fix / Troubleshooting
Safety first: Disconnect power before removing the control panel or main board cover.
This alarm points to an internal electronics fault rather than a simple sensor or wiring issue.
- Step 1 – Power cycle:
- Turn off power at the breaker for at least 5 minutes.
- Restore power and check if the alarm clears.
- Step 2 – Check supply quality:
- Ensure the supply voltage is stable and within Nibe’s specified range.
- Look for signs of water ingress or condensation on the control board.
- Step 3 – Firmware:
- If your model supports it, check for available firmware updates via Nibe’s service tools (technician task).
If A15 persists, the control board likely needs replacement by an authorized Nibe service technician.
Repair Difficulty
Required Part
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