I have had a Kedel 30 kW pellet boiler since 2015 and last year the O2 reading dropped to zero and the fan kept running but the pellet feeder stopped. Turns out the O2 sensor had failed. I used the menus to set the boiler to not use the O2 sensor while I researched where to get a replacement. This option is in the menus under O2 Control and then the O2 Control Method, and turn it to either OFF or Show.
I found what looked to be the same sensor with the proper connector on ebay, search for WO163304. They work once you use the Kedel menu system to calibrate the new sensor. This option is in the menus under O2 Control and then O2 Probe Calibration. This option only appears when the boiler is running. You need to have the sensor out of the flue pipe in the open air. I did my calibration just as the boiler was starting so nothing was hot.
Disconnect the sensor from the wire harness
Unscrew the O2 sensor out of the flue.
Reconnect the sensor wiring and place sensor on a surface that can stand heat (not paper, wood or plastic)
Start up the boiler (I just turned up the thermostat)
Wait 15 minutes to let the O2 sensor get hot (It has an internal heater and will get very hot)
Use the Kedel menu mentioned above to re-calibrate the O2 sensor, it took a few seconds
In my case there was a value of 120 before calibration and 72 after.
Disconnect the sensor plug and let it cool down and then carefully screw the sensor back into the flue
Re-connect the sensor
Go into the menu and change the O2 Control Method to Yes or ON and in a few seconds the O2 reading should appear on the screen of your boiler
Before I calibrated the sensor I was getting Actual O2 Readings of around 19 and 20% even though the "Required" levels were around 10 to 15% and it did not appear that the boiler was fully burning the pellets. Now the Actual and Required O2 levels are almost identical.
I found what looked to be the same sensor with the proper connector on ebay, search for WO163304. They work once you use the Kedel menu system to calibrate the new sensor. This option is in the menus under O2 Control and then O2 Probe Calibration. This option only appears when the boiler is running. You need to have the sensor out of the flue pipe in the open air. I did my calibration just as the boiler was starting so nothing was hot.
Disconnect the sensor from the wire harness
Unscrew the O2 sensor out of the flue.
Reconnect the sensor wiring and place sensor on a surface that can stand heat (not paper, wood or plastic)
Start up the boiler (I just turned up the thermostat)
Wait 15 minutes to let the O2 sensor get hot (It has an internal heater and will get very hot)
Use the Kedel menu mentioned above to re-calibrate the O2 sensor, it took a few seconds
In my case there was a value of 120 before calibration and 72 after.
Disconnect the sensor plug and let it cool down and then carefully screw the sensor back into the flue
Re-connect the sensor
Go into the menu and change the O2 Control Method to Yes or ON and in a few seconds the O2 reading should appear on the screen of your boiler
Before I calibrated the sensor I was getting Actual O2 Readings of around 19 and 20% even though the "Required" levels were around 10 to 15% and it did not appear that the boiler was fully burning the pellets. Now the Actual and Required O2 levels are almost identical.
