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Error code reference

Ariston Cooktop Error Code E.25

Dissipator temperature sensor Supplying Generator in open circuit (CO).

Ariston codesAriston cooktop codes

Dissipator temperature sensor Supplying Generator in open circuit (CO).

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What E.25 means on a Ariston cooktop

Error code E.25 on an Ariston induction cooktop indicates that the dissipator temperature sensor associated with the supplying generator has been detected in an open circuit condition. The dissipator temperature sensor monitors the thermal state of the heat sink (dissipator) that cools the power electronics within the induction generator module. An open circuit fault means the control board is receiving no signal from this sensor, which typically occurs when the sensor circuit is broken, disconnected, or the sensor element itself has failed to a high-resistance or infinite-resistance state.

The supplying generator in an induction cooktop is the power inverter assembly responsible for producing the high-frequency alternating current that drives the induction coils. Because this component generates significant heat during operation, its associated dissipator (heat sink) must be continuously monitored to prevent thermal runaway and component damage. The temperature sensor embedded in or attached to this dissipator is critical for safe operation. When the control board detects an open circuit on this sensor input, it triggers E.25 and typically halts operation to protect the power electronics.

Common causes include a broken or disconnected sensor wire harness, a failed NTC or thermocouple-type sensor element that has gone open, corrosion at the connector terminals, or physical damage to the sensor from prior overheating events. Because this fault directly involves the high-voltage power electronics section of the cooktop, diagnosis and repair should be approached carefully, with the unit fully unplugged before any internal inspection.

Source: manufacturer service documentation.

Common causes of E.25

  1. 01

    Disconnected or loose sensor wiring harness

    Wiring / connection

    The connector linking the dissipator temperature sensor to the control board may have vibrated loose or become fully disconnected. Visually inspect all connectors near the heat sink and generator module for proper seating.

  2. 02

    Failed temperature sensor (open circuit)

    Part replacement

    The sensor element itself may have failed internally, producing infinite or unmeasurable resistance. This is a common failure mode for NTC thermistors exposed to repeated thermal cycling or a prior overheating event.

  3. 03

    Damaged or broken sensor wire

    Part replacement

    The wire between the sensor and the control board may have a break in the conductor, caused by physical stress, pinching during assembly, or heat damage. Continuity testing of each wire in the sensor circuit will identify this fault.

  4. 04

    Corroded or oxidized connector terminals

    Wiring / connection

    Moisture or heat exposure can cause oxidation at the sensor connector pins, increasing resistance to the point where the circuit appears open to the control board. Inspect terminals for discoloration or buildup and clean or replace the connector as needed.

  5. 05

    Faulty control board sensor input

    Part replacement

    If the sensor, wiring, and connectors all test correctly, the sensor input circuit on the main control board itself may be damaged. This is the least common cause but should be considered after all other components are ruled out.

See the test procedure for each cause

Frequently asked questions about E.25

What does E.25 mean on a Ariston cooktop?
E.25 means the cooktop has detected an open circuit in the dissipator temperature sensor for the supplying generator. This sensor monitors the heat sink that protects the cooktop's internal power electronics. Because the control board cannot read a valid temperature signal, the cooktop shuts down to prevent potential damage to the generator components.
Can I fix E.25 on my Ariston cooktop myself?
Some causes, such as a loose connector, can be addressed by a knowledgeable DIYer after fully unplugging the unit. However, the fault is located in the high-voltage power electronics section of the cooktop, so internal inspection carries risk if you are not experienced with appliance repair. Replacing the sensor or control board typically requires basic tools and component sourcing, but if you are unsure, a qualified technician is the safer option.
Is it safe to keep using my Ariston cooktop while E.25 is showing?
No. E.25 indicates the cooktop cannot monitor the temperature of its internal power electronics. Continuing to operate the unit in this condition risks overheating the generator module, which could cause further component damage or create a safety hazard. The cooktop should remain unplugged until the fault is diagnosed and repaired.
Will resetting the cooktop clear the E.25 error?
A power reset by unplugging the unit for a few minutes may temporarily clear the error if the fault was caused by a transient glitch. However, if the underlying cause is a physically broken sensor, a broken wire, or a failed connector, the error will return as soon as the cooktop attempts to read the sensor again. A reset alone does not fix the fault.
How much does it cost to repair E.25 on an Ariston cooktop?
Repair costs vary depending on the root cause. Replacing a dissipator temperature sensor typically falls in the range of $20 to $80 for the part, plus labor if a technician is used. If the main control board requires replacement, costs can range from $100 to $300 or more for parts alone. A diagnostic service call generally adds $50 to $120 depending on your location.

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