Vokera water heater displays code 05, unit shuts down or will not start, temperature reading appears abnormal
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 power before removing the front cover. Surfaces may be hot; allow the unit to cool.
Owner checks:
- Perform a reset from the control panel. If the code reappears immediately, a sensor or wiring fault is likely.
- Visually check that no external cables to the heater are trapped or damaged.
Engineer checks:
- Identify the faulty NTC sensor (flow, return, or DHW) as indicated by the service manual for the specific Vokera model.
- Measure the sensor resistance at room temperature and compare with Vokera’s resistance/temperature chart; replace if out of tolerance.
- Inspect and repair any damaged wiring or loose connectors between the NTC and the PCB.
- Ensure the sensor is firmly clipped to the pipe with thermal paste or proper contact.
Sensor replacement is relatively straightforward for a trained engineer and usually does not require draining the entire system.
Repair Difficulty
Required Part
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