Ariston Oven Error Code ER09

ER09 indicates that the oven's control system has detected a disconnection or short circuit in the circuit for Potentiometer 2, which is a knob-position sensor used on rotary control models. The oven cannot determine the correct control input and halts normal operation as a result. This error does not apply to Ariston ovens with Touch controls, as those models do not use potentiometers.

You should not attempt to operate the oven while this error is active. The fault means the control system cannot correctly read the input from Potentiometer 2, which could prevent the oven from responding correctly to your settings. Continuing to use it in this state could lead to unpredictable behavior or further component damage.

Repair costs depend on what is causing the fault. If only a connector needs to be reseated, the cost is minimal and may just cover a service call, typically in the range of $75 to $150. Replacing a potentiometer is a relatively affordable parts-and-labor repair, often $100 to $250. If the control board needs replacement, costs can rise to $200 to $450 or more depending on parts availability and labor rates in your area.

If you are comfortable working with appliance wiring, you can inspect the connectors and wiring harness leading to Potentiometer 2 for obvious damage or loose connections. Testing the potentiometer with a multimeter is also within reach for a knowledgeable DIYer. However, if the fault is traced to the control board or requires component replacement, professional repair is recommended to avoid further damage.

A power reset by switching off the oven at the breaker for a few minutes may temporarily clear the error display, but it will return if the underlying fault in the potentiometer circuit has not been resolved. The root cause, whether a loose connector, damaged wire, or failed component, must be identified and corrected for the error to stay cleared.