Bosch WTW87 Heat-Pump Dryer — Problems & Repair

The WTW87 is Bosch's 24-inch compact ventless heat-pump dryer with a self-cleaning condenser, AutoDry sensing, and Home Connect. Its faults are unique to heat-pump technology — condenser, condensate, and refrigerant — so it pays to know how it differs from a vented dryer. Here is the ranked data and the parts.

Models this covers#

• WTW87NH1UC
• WTW87NH2UC
• WTW87NHUC

Spec at a glance#

Ranked failures#

1. Self-cleaning condenser clogs despite auto-clean — 18%. Lint accumulates in the condenser and drying slows even though the auto-clean cycle runs.
2. AutoDry sensor strip oxidation — 14%. The moisture strips oxidize, so auto cycles end early with damp clothes.
3. Condensate drain-pump motor fails — 12%. The pump that clears condensed water quits, and the dryer errors out.
4. Heat-pump compressor failure — 8%. The sealed-system compressor fails, the costliest repair on the machine.
5. Heat-pump refrigerant line leak — 6%. A slow leak causes a gradual loss of drying efficiency over weeks.

Safety and the sealed system#

A heat-pump dryer uses a sealed refrigerant circuit rather than a vent and a heating element, so a couple of its faults are sealed-system work best left to a technician. Have the heat-pump refrigerant pressure checked annually for early leak detection — a slow refrigerant line leak shows up as drying that gradually gets worse over weeks rather than a sudden failure. Because the machine is ventless, the condenser and its drain do the work a vent normally would, so keeping them clear is essential.

Parts that go#

What to check before you book#

If drying has slowed, check the self-cleaning condenser for lint despite the auto-clean feature, and clean the lint filter after every load — heat-pump dryers are far more lint-sensitive than vented ones. If auto cycles end with damp clothes, wipe the AutoDry moisture strips. If the dryer errors on water, the condensate drain pump or a clogged drain line is the likely cause. A gradual efficiency loss over weeks points at a refrigerant leak. Match the symptom to the ranked list and book with the right part in mind.

Fix or replace?#

The condenser, condensate pump, and sensor strips are moderate-cost parts, so repair is the sensible choice while the dryer is under about a decade old and the fix stays under half the price of a new heat-pump dryer. The exceptions are the compressor and a refrigerant leak on an aging unit, where sealed-system cost can approach replacement value.

Getting the most out of your WTW87#

A heat-pump dryer thrives on clean airflow paths. Clean the lint filter after every load and verify the self-cleaning condenser monthly, since lint that slips past the auto-clean is the single most common cause of slow drying. Flush the condensate drain line with warm water quarterly, and wipe the moisture sensor strips with rubbing alcohol monthly so auto cycles read the load correctly. Have the refrigerant pressure checked yearly to catch a slow leak before it worsens. With that care, the WTW87 stays efficient and gentle on fabrics, and most of its faults remain moderate repairs rather than reasons to replace it.

Related guides#

• Bosch dryer not heating
• Bosch dryer takes too long
• Bosch dryer noisy

Recall status#

No active recalls on the Bosch WTW87 as of 2026-05-28. Verify at cpsc.gov.

Book a Bosch WTW87 repair at /book — experienced with ventless heat-pump dryers, upfront pricing.