What PRESSURE SENSOR FAULT Means
WHICH MACHINES THIS APPLIES TO: Asko's professional washers - the WMC-series machines installed in communal laundry rooms, care homes, salons, gyms and small commercial laundries - do not report problems as numbers. They print the problem on the display in words. Two document families stand behind the messages on this site and they are deliberately kept apart, because they are not the same book and they do not use quite the same wording.
THE OLDER PLATFORM: the Asko service documentation for the new generation of washing machines whose circuit diagrams are labeled WMC55. Its problem section states that if a problem occurs during a program cycle it is shown on the display after the program has finished or been interrupted - which is worth knowing, because on this platform the message often appears at the end rather than at the moment something went wrong.
THE LATER PLATFORM: the operating instructions for the WMC64P and the WMC743VS, which both state that a message is shown on the display if an error occurs during the program. The message set in those two books is identical to each other, which is good corroboration of both.
A LIMIT WORTH STATING: no public document could be found under the model numbers WMC6743 or WMC6744. The messages here are attributed to the books they were read in and are not claimed to cover those models.
ONE PRACTICAL NOTE BEFORE ANY CHECK: a professional washer is usually hard-wired rather than plugged in, so isolating it means the breaker or the wall isolator that feeds it, not a plug. And in a communal or commercial room the machine belongs to somebody else. If that is your situation, the checks below are for the person who looks after the machines, and reporting the exact wording on the display is the most useful thing a user can do.
WHAT THE WMC55 PLATFORM SAYS IT MEANS: the problem list reads "A drop in pressure has been detected in the first rinse. This could be due to leakage in the level sensor or in the hose leading to it. The washing program has been interrupted." Three separate facts in one entry, and all three are useful.
FACT ONE, WHEN IT LOOKS: in the first rinse. This is not an error the machine can raise at any point in the program - it is a specific measurement taken at a specific stage, which is why the machine usually stops part way through rather than at the end.
FACT TWO, WHAT IT SUSPECTS: leakage in the level sensor or in the hose leading to it. A washer measures how much water is in the drum by air pressure in a small chamber and a thin hose up to the sensor. If that path leaks air, the level the machine reads is lower than the level in the drum - and a machine reading low is a machine inclined to put more water in.
FACT THREE, WHAT IT DOES: interrupts the program. It does not finish the wash. That is the machine declining to run the rest of a cycle on a measurement it has caught out.
WHY THE SEVERITY IS NOT LOW: the same measurement path is what protects against overfilling. A commercial washer that cannot trust its level reading is a machine that could put water where you do not want it, in a room where that water runs along a line of machines.
CLASSIFICATION: problem, program interrupted, with a water-escape risk behind it. No owner repair is published.
Common Causes of PRESSURE SENSOR FAULT
- Leak in the hose between the pressure chamber and the level sensor
- Level sensor itself leaking or failing
- Pressure chamber partly blocked with detergent residue or fiber
- Hose kinked, split or knocked off after the machine was moved
- Control unit misreading a sound sensor
🔧 One Safe Check You Can Try
Take the machine out of service rather than restarting it to see whether it gets further. The measurement the machine has caught out is the same one that keeps it from overfilling, so another attempt is a poor bet in a room with a floor you care about. Shut the water tap to the machine and leave it closed while it waits. If there is water in the drum, empty it the way the manual for your platform says and note roughly how much came out, because a level that was wrong is part of the picture. Look at the floor under and around the machine and along the plinth line of the machines either side, and note anything you find. Then write down what the machine did: at what point it stopped, whether the drum looked fuller or emptier than usual through the glass, and whether it has been moved or had work done near it recently, since a pressure hose that has been knocked off or kinked behaves exactly like one that has split. Do not open the cabinet after the pressure chamber or its hose: it sits under the drum next to the pump wiring, and the machine is isolated at its breaker or wall isolator first.
⚠ Why You Shouldn't Go Further Than That
- The level measurement is what stands between the machine and an overfill, so a machine that has reported this is not restarted to see whether it manages the next cycle.
- The pressure chamber and its hose sit under the drum alongside the pump wiring, reachable only with the machine isolated at its breaker or wall isolator and moved, which on a commercial installation may mean unbolting it.
- A split in a thin air hose is found by testing rather than by eye, so opening the machine without instruments simply exposes live 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.