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Error code reference

Hotpoint Cooktop Error Code F17

ISI UART 2

Hotpoint codesHotpoint cooktop codes

ISI UART 2: Excessively high temperature on the small induction coil.

First step from the service manual

Check whether the induction coil NTC has become miscalibrated.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What F17 means on a Hotpoint cooktop

The F17 error code on a Hotpoint induction cooktop indicates an excessively high temperature reading on the small induction coil, as detected through the ISI UART 2 communication channel. The ISI (Induction System Interface) UART (Universal Asynchronous Receiver-Transmitter) is the serial communication protocol used internally to relay sensor data between the induction control board and the individual coil assemblies. When the NTC (Negative Temperature Coefficient) thermistor monitoring the small coil reports a temperature value that exceeds the acceptable operating threshold, the control system triggers F17 and typically disables that coil to prevent damage.

The NTC thermistor works by decreasing its electrical resistance as temperature rises. The control board interprets these resistance changes as temperature readings. If the thermistor becomes miscalibrated, physically damaged, or develops a poor connection, it can report falsely elevated temperatures even when the coil is operating normally. Conversely, the code can also appear when the coil genuinely is overheating, which may result from blocked ventilation, a faulty cooling fan, or a defective coil driver circuit.

The first diagnostic step is to check whether the NTC thermistor on the small induction coil has become miscalibrated or has drifted out of its correct resistance range. This involves measuring the thermistor resistance at a known ambient temperature and comparing it against the expected specification. A thermistor reading outside the normal range at room temperature confirms a faulty sensor rather than an actual overtemperature condition in the coil itself.

Source: manufacturer service documentation.

Common causes of F17

  1. 01

    Miscalibrated or faulty NTC thermistor

    Part replacement

    The NTC thermistor on the small induction coil can drift out of its calibrated resistance range over time, causing it to report excessively high temperatures even when the coil is cool. Measuring the thermistor resistance at room temperature and comparing it to the expected specification will confirm whether the sensor has failed.

  2. 02

    Poor or corroded thermistor connection

    Wiring / connection

    A loose, corroded, or intermittent connector between the NTC thermistor and the control board can cause erratic resistance readings that the system interprets as an overtemperature condition. Inspecting the thermistor wiring harness and connector pins for corrosion or poor seating is an important early step.

  3. 03

    Blocked or restricted ventilation

    Wiring / connection

    Induction coils rely on adequate airflow to stay within safe operating temperatures. If the cooktop ventilation slots are blocked or the cooling fan is not functioning properly, the small coil can genuinely overheat and trigger the F17 code.

  4. 04

    Faulty cooling fan

    Part replacement

    If the internal cooling fan has failed or is running below its required speed, heat from the induction coil cannot dissipate properly. This leads to a real temperature rise that the thermistor correctly detects, resulting in an F17 fault.

  5. 05

    Defective small induction coil or driver circuit

    Part replacement

    In some cases, a fault within the small induction coil itself or in the associated driver circuit on the control board can cause excessive heat generation during operation. This is typically confirmed after ruling out thermistor and ventilation issues.

See the test procedure for each cause

Frequently asked questions about F17

What does F17 mean on a Hotpoint cooktop?
F17 on a Hotpoint cooktop means the control system has detected an excessively high temperature on the small induction coil, as reported through the ISI UART 2 communication channel. The most common starting point is checking whether the NTC thermistor monitoring that coil has become miscalibrated or failed. The cooktop disables the affected zone as a safety measure until the fault is resolved.
Can I fix the F17 error myself, or do I need a technician?
Some basic checks, such as clearing blocked ventilation and inspecting the wiring connector to the thermistor, can be done by a careful DIYer comfortable working with appliances. However, measuring the NTC thermistor resistance and replacing components like the thermistor, cooling fan, or control board typically requires disassembly and some technical knowledge. If you are not experienced with induction appliance internals, a qualified technician is the safer choice.
Is it safe to keep using my Hotpoint cooktop when F17 is displayed?
You should not continue using the affected small induction zone while the F17 code is active. The cooktop disables that zone precisely because a temperature condition outside safe parameters has been detected. Using the appliance without resolving the fault risks further component damage and, if the overheating is genuine rather than a sensor error, a potential safety hazard.
Will resetting the cooktop clear the F17 error code?
A power reset by switching off the cooktop at the circuit breaker for a few minutes may temporarily clear the F17 code, but it will return if the underlying cause has not been addressed. A miscalibrated thermistor, faulty fan, or genuine overtemperature condition will continue to trigger the fault during normal operation. A reset is useful for confirming whether the error is intermittent, but it is not a repair.
How much does it cost to repair an F17 error on a Hotpoint cooktop?
Repair costs depend on the root cause. Replacing an NTC thermistor is generally a lower-cost repair, typically in the range of $50 to $150 including parts and labor. If the fault involves the cooling fan or the induction control board, costs can rise to the $150 to $400 range depending on the specific components and local labor rates. Getting a diagnostic assessment before committing to a repair is always recommended.

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