E09
BWT Perla
Temperature Sensor Fault
Display shows E09 and the unit reports a temperature or frost protection error
Advertisements
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.
Advertisements
Possible Causes
Defective NTC temperature sensor on valve head, Sensor cable damaged or disconnected, Sensor not properly seated in its well, Controller misreading due to moisture on PCB
How to Fix / Troubleshooting
Safety first: Disconnect power. Do not operate the BWT Perla in freezing conditions; damage to the resin vessel and valve can occur.
- Locate temperature sensor: On many BWT Perla models, the NTC sensor is clipped to the valve body or inserted into a sensor well. Refer to the service diagram if available.
- Inspect connection: Check the sensor plug at the control board and at the sensor body. Reseat both ends.
- Check for moisture: Remove the control cover and inspect the PCB for condensation or water traces. Dry gently with a cloth and allow the unit to air dry before reassembly.
- Environmental check: Ensure the installation room is above the minimum temperature specified by BWT (typically above 4–5°C). If the unit has been frozen, have a technician inspect for cracks.
- Replace sensor if needed: If E09 persists after drying and reseating, replace the NTC temperature sensor with the correct BWT Perla spare.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
NTC Temperature Sensor
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements