Thermostat displays E15 and cannot detect the boiler type or configuration.
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: Isolate mains power to the boiler before adjusting any control wiring.
Steps to check:
- 1. Verify compatibility: Confirm that your Baxi smart thermostat model is approved for use with your specific Baxi boiler model and control interface.
- 2. Check wiring: Ensure the control cable is connected to the correct low-voltage terminals on the boiler (e.g. OpenTherm/EBUS) and not to 230 V terminals.
- 3. Manual configuration: If auto-detection fails, use the thermostat’s installer menu to manually select the boiler type and control mode as per the boiler manual.
- 4. Firmware update: Update the thermostat firmware to the latest version to ensure support for newer boiler models.
When to call a professional: If E15 persists with correct wiring and compatible equipment, a heating engineer should check the boiler’s control board and interface.
Repair Difficulty
Required Part
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