The short answer
On Bosch WTW dryer there are two different faults hiding behind one complaint: a cycle that ends too soon, and a cycle that never ends at all. The first points at sensing, the second at airflow or at a condition the machine cannot satisfy. Deciding which one you have on the one model this family covers, WTW87NH1UC is the first step and it costs nothing.
What you observe on these models
- An indicator or symbol appears part way through — A reservoir, a filter or a maintenance prompt, depending on what your model has.
- The load comes out dry in places and wet in others — Uneven drying points at loading or at air distribution rather than at the control.
- The problem is worse with big or heavy loads — Load-dependent behaviour points at airflow and sensing rather than at electronics.
- It completes on a timed programme but not on a sensing one — One of the most useful observations available, and it points squarely at sensing.
- NEAR MISS - the machine will not begin at all — That is a start fault, and it belongs on the no-start page for this family.
Causes, most likely first on the WTW family
- Moisture sensing misreading the load — First on the WTW family for cycles that end early. The sensor reads the load through contact, so residue from softener sheets, or a small load that touches it rarely, reads as dry. Nothing is broken and nothing needs replacing; the surface needs cleaning and the habit needs changing.
- A restricted air path — Second, and the cause of cycles that run long rather than short. Filters, secondary filters and condensers all restrict gradually, so owners experience it as the machine getting slower rather than as a fault.
- A condition the machine is waiting on — Third. A full reservoir, a prompt that has not been acknowledged, or a door that has been opened and not properly reclosed will hold a cycle indefinitely while the panel looks normal.
- Control, sensor wiring or a thermal device — Last. Genuine faults, but they are outnumbered on WTW87NH1UC by the three above, all of which are owner-fixable.
Check in this order, and why
- First: decide whether it ends early or never ends — Two different faults with two different causes. An early finish with a wet load is sensing; a cycle that runs on is airflow.
- Second: run the same load on a timed programme — The single most useful test on WTW87NH1UC. A timed cycle that dries properly proves the heat and the air are fine and puts the fault on the sensing side.
- Third: clean the sensing surface and the filters — Wipe the sensor contacts with a little vinegar or detergent on a cloth to remove softener residue, and clear every filter the machine has.
- Fourth: empty any reservoir and clear any prompt — Then run a normal cycle. If the fault is gone, the cause was maintenance rather than a failure.
Before you open anything
Safety
Unplug the dryer or switch off its breaker before removing any panel or reaching past a filter housing; a capacitor can hold a charge after the power is off. Do not hold the door switch closed to watch a cycle run with the door open, and do not run the machine with any filter missing - the filter is what keeps lint out of the parts that get hot.
Models in the WTW family
Reference| Model number | Family key |
|---|---|
| WTW87NH1UC | bosch:dryer:wtw |
When to call a technician
Everything on the owner side of this fault is maintenance: filters, reservoir, sensor surface, and the choice of programme. Once those are done on WTW87NH1UC and the fault survives, the next step is measurement rather than inspection, and that is a service call. Note what the panel showed at the moment it stopped before you clear it.
Sources — The symptom-report corpus recorded against Bosch WTW dryer pages for this fault is cited below. No share is quoted from it anywhere on this page: the snapshot reaches this page as a provenance chain without values, so every ordering here is technician judgement rather than a measured proportion.
Documented- amazon-reviews — amazon-reviews, fetched 2026-09-02
Other faults covered for the WTW family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
