What THERMISTOR FAULT Means
WHICH MACHINES THIS APPLIES TO: Asko washers with a text window rather than a numeric display report their problems in words. The Use and Care Guides for the US W6761, W640 and W660 carry one such table; the operating instructions for the W8844XL and the W6884 Eco carry another; and the WM60 service manual carries the problem-indication tables for the WM60.2 and WM60.3 panels. The wording varies between them, and the section below says which document each form comes from. All of these machines clear the message the same way, by turning the machine off and then back on.
WHAT ASKO PRINTS FOR THE OWNER: the W6761, W640 and W660 guide gives "Call a service technician."
WHAT THE SERVICE DOCUMENTATION ADDS: the W600-series service manual reads "The washing program has finished without heating. The thermistor is failing or short-circuited." The WM60 service manual describes the same error on its own platform with three conditions: "The circuit for the thermistor is open", the sensor being failing, and the measured value falling outside the safe range, which it gives as above 120 degrees Celsius, or 248 degrees Fahrenheit.
WHY A READING ABOVE 120 DEGREES IS TREATED AS A SENSOR FAULT: because water in a washing machine cannot reach it. A reading that high is not a description of the drum; it is a sensor or a circuit misbehaving, and the control is right to reject it rather than act on it.
WHAT THE THERMISTOR DOES: it is the temperature sensor at the drum assembly, and it is the only thing telling the control how hot the wash water is. Every heated program is run by switching the element on and watching that sensor.
WHAT HAPPENS TO THE PROGRAM: on the W600 generation the program finishes without heating, which means the laundry comes out clean and cold rather than the machine stopping. On the WM60 platform the wash cycle is interrupted. Both are the control declining to run a heating circuit it cannot measure.
THE RELATED MESSAGE: "Temperature stop problem" reports that the water did not get hot without naming a part. This one names the sensor. Note which of the two your machine showed, because it changes where a technician starts.
CLASSIFICATION: problem, on the sensing side.
Common Causes of THERMISTOR FAULT
- Thermistor circuit open, which the WM60 manual names first
- Thermistor short-circuited, which the W600 service manual names directly
- Sensor reading outside the safe range, given as above 120 degrees Celsius on the WM60 platform
- Connector at the sensor loose, corroded or opening as the machine warms
- Wiring between the sensor and the control damaged
- Control unit misreading an otherwise sound sensor
🔧 One Safe Check You Can Try
There is no owner repair for this and no published check, so the useful work is describing the behavior precisely. Note whether cold programs run through normally while heated ones do not, because that alone confirms which part of the machine is involved. Note whether the problem appears at the same point in every cycle or at different points, and whether it is constant or intermittent; an intermittent problem appearing once the machine has been running for a while usually means a connector opening as things warm and move rather than a failed sensor, and that changes what a technician looks at first. Note whether the laundry has been coming out cold for some time before the message started, because that dates the problem. If the machine is going to wait for a visit, switch it off at the outlet or the breaker and leave it off. Do not open the cabinet: the thermistor is mounted at the outer tub with its wiring in the same loom as the heating element, the element terminals are live whenever the machine is connected, and reaching any of it means working around a spring-suspended drum.
⚠ Why You Shouldn't Go Further Than That
- The thermistor sits at the outer tub with its wiring in the same loom as the heating element, which is at mains potential whenever the machine is connected to power.
- Reaching that area means dismantling around a spring-suspended drum rather than removing a single panel.
- A resistance reading is only meaningful with the machine isolated and the connector disconnected, so there is nothing useful to measure on a live machine.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.