E17 appears and the thermostat reports a configuration or parameter error; some menus may be locked.
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: Configuration changes are low risk; ensure you have access to installation documentation.
- Restore default configuration: Use the installer menu to restore default parameters: Menu > Installation > Default settings.
- Reconfigure step-by-step: Re-enter system type (boiler, heat pump, underfloor), sensor types, and outputs carefully, saving after each step.
- Factory reset: If E17 persists, perform a full factory reset and set up the thermostat as a new device in the Tydom app.
If configuration cannot be saved without E17 reappearing, the internal memory is likely defective and the thermostat should be replaced.
Repair Difficulty
Required Part
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