What THERMISTOR FAULT Means
WHICH MACHINES THIS APPLIES TO: this message appears on two different parts of Asko's professional line, and the two are kept in separate sections below because they are different machines with different consequences. The washers are the WMC-series professional machines. The dryers are the TDC33 and TDC44 commercial tumble dryers, from the industrial dryer service manual for that range. Neither of them uses numbered codes - both print words on the display.
THE PROFESSIONAL WASHER - WHAT IT MEANS: the WMC55 error list reads "The thermistor is failing or short-circuited. The washing program has finished without heating." Two things are being told to you there. The sensor circuit is either open or shorted, and the wash you have just taken out was done cold. On this platform the problem is shown after the program has finished or been interrupted, so the load is already out of the machine by the time anyone reads it.
WHY THAT MATTERS MORE IN A COMMERCIAL ROOM THAN AT HOME: in a care home, a salon, a gym or a food environment the wash temperature is often the point of the wash. A machine that completes a cycle without heating produces laundry that looks washed and has not been through the temperature it was supposed to reach. Anybody responsible for that room needs to know which loads went through while the message was showing.
THE COMMERCIAL DRYER - WHAT IT MEANS: the TDC33 and TDC44 service manual prints "Thermistor problem" with the remedy "change thermistor", and its problem-indication section adds that the program stops and the display shows the message, that the thermistor may have become disconnected or have an internal problem, and that a serviceable thermistor measures between 60 and 40 kOhm at 20 to 30 degrees Celsius. That resistance figure is a technician's measurement, quoted here so the reader knows the question is settled with a meter rather than by opinion. The same manual also uses the wording "Thermistor error" for this indication.
THE DIFFERENCE IN BEHAVIOR, WHICH IS THE PRACTICAL POINT: the washer finishes the program without heating. The dryer stops. Same part, same message, two different responses, and no reader should carry one across to the other.
CLASSIFICATION: problem on both machines. Neither book gives an owner procedure for it.
Common Causes of THERMISTOR FAULT
- Thermistor failed, open circuit or short circuited
- Thermistor disconnected or its connector disturbed
- Wiring between the sensor and the control damaged, often where it flexes
- Control unit not reading an otherwise sound sensor
- On a dryer, airflow so restricted that temperatures ran well outside the expected range
🔧 One Safe Check You Can Try
There is no owner repair here and no setting to change, so the useful work is in the record and in the housekeeping. On a washer, find out which loads ran while the message was appearing, because they were washed without heating, and anything washed for hygiene rather than appearance needs doing again once the machine is right. Note whether the message appears on every program or only on hot ones, and whether it began after the machine was moved or after work in the room, since a disconnected sensor and a failed sensor look identical on the display and quite different behind it. On a commercial dryer, do the routine maintenance first for the plain reason that a machine running hot through blocked filters puts temperatures outside their normal range and can look like a sensor problem: let it cool, clean the door filter properly, clean the fan housing and the condenser unit on models that have one, and empty the condensation tank. Then hand it over. Do not test the sensor yourself - both machines are isolated at a breaker or wall isolator rather than a plug, and the thermistor and its wiring sit inside the cabinet with the heating circuit.
⚠ Why You Shouldn't Go Further Than That
- Neither book publishes an owner procedure for this message - the dryer manual states the remedy as changing the thermistor, which is service work.
- The sensor and its wiring sit inside the cabinet alongside the heating circuit, and a professional machine is isolated at its breaker or wall isolator rather than by pulling a plug.
- Measuring a thermistor means reading resistance against a published figure at a known temperature, which needs a meter and the machine in a known state rather than a guess at the parts.
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.