Frigidaire Range Error Code E21

E21 indicates a loss of communication between the User Interface Board (UIB) and the pan sensing PCB. This means the two control boards are not exchanging data as required for normal operation. The fault is typically caused by a wiring harness problem or a failed circuit board. A technician should inspect the harness first, then proceed to board replacement if needed.

An E21 fault points to a communication failure in the control system, which can affect how the range manages its cooking surface. Continuing to use the range while this error is active is not recommended, as the control system may not operate reliably. It is best to stop using the range and have it diagnosed before cooking on it again.

Resetting the range by cutting power at the breaker for a few minutes may temporarily clear the E21 code, but the fault will return if the underlying communication problem has not been resolved. A reset does not repair a damaged harness or a failed board. A full diagnostic following the prescribed steps is necessary to permanently clear the error.

A knowledgeable DIYer can start by checking that the wiring harness connectors between the UIB and pan sensing PCB are fully seated and free of visible damage. If the wiring is intact, replacing the pan sensing PCB or UIB requires identifying the correct part and comfort working inside the appliance's control area. If you are not experienced with appliance electronics, having a qualified technician perform the repair is the safer approach.

Repair costs depend on which component has failed. A wiring harness repair or connector fix is typically the least expensive path, often falling in the range of $75 to $150 for a service call if no parts are needed. Pan sensing PCB replacement generally adds $50 to $150 in parts costs, while UIB replacement can range from $100 to $250 or more depending on the model. Labor costs will vary by region and service provider.