Moisture Sensor Fault? Why Your Dryer Misjudges Dryness in Solihull

A moisture sensor works by passing a small current across metal bars inside the drum and measuring how easily that current flows through the damp fabric. Wet clothes conduct more than dry ones, so the reading falls as the load dries and the machine ends the cycle when it reaches the target. Anything that interferes with that reading, coating on the bars, a broken wire, a poor earth connection or a board that misinterprets the signal, will make the dryer stop at the wrong moment.

Symptoms that point to the sensor

Loads finishing damp while the machine insists the cycle is complete. Cycles running to the maximum time every time, as though no dryness reading is being received. Over-dried, brittle laundry. Error codes relating to moisture or sensor. Behaviour that changes with fabric type in ways that do not make sense. A dryer that works normally on timed programmes but badly on sensor programmes is a strong indicator.

Cleaning the bars

With the machine off and unplugged, open the door and look for two or three metal bars inside the drum, usually near the door opening or on the rear wall. Wipe them with a soft cloth dampened with a little white vinegar or plain water, then dry them. Fabric softener and detergent residue coat the bars with a film that insulates them, and this is one of the most common causes of early cycle endings. Do not scrape the bars or use abrasives.

What we test

We measure continuity and resistance across the sensor bars and check their insulation from the drum. The wiring between the sensor and the board is inspected for chafing or a broken conductor, and the earth path is confirmed, because a poor earth distorts the reading. We then check what the board does with the signal, using stored fault codes and live readings where the model supports them. Only then do we decide whether the sensor, the harness or the board needs replacing.

Causes beyond coating

Broken sensor wires after years of drum movement. Corroded connections at the sensor terminals. A board whose sensing circuit has drifted. A drum earth strap that has failed. On some models the sensor is part of a harness that also carries other signals, so an intermittent fault elsewhere can affect dryness readings. These are the cases where replacing the bars alone would not solve the problem.

Parts and cost

Sensor bars and harnesses are usually inexpensive and available. A board is the expensive outcome and is only recommended when testing shows the sensing circuit has failed. We identify parts from the model plate, quote them separately and order after your approval. Availability on older models can be limited and we will say so.

Safety

The sensor circuit is low voltage, but the machine still contains mains wiring and a heater, so do not remove panels yourself. Never bridge the sensor bars to force a cycle to end, and never disable the dryness function by running only timed cycles as a permanent workaround, because over-drying shortens fabric life and stresses the appliance.

Better drying habits

Clean the sensor bars monthly if you use softener, or stop using softener sheets, which leave residue on the bars and on the drum. Shake out laundry so damp and dry items are mixed evenly. Use the sensor programme rather than a timed one so the machine can do its job, and keep loads to a sensible size.

Booking

Tell us whether the problem appears on sensor programmes only, whether the load is damp or over-dried, and any error code. Mention if you use fabric softener regularly, and whether the bars look coated. That helps us decide whether a clean and test is likely to be enough.