F03 — Condensate Not Draining

How to fix it

1. Verify ambient temperature is above 50°F where the dryer is installed.
2. Unplug the dryer.
3. Remove the kickplate and access the heat exchanger behind the slide-out condenser.
4. Carefully clean dust and lint from the evaporator/condenser fins with a soft brush and vacuum.
5. Ensure both lint filters and the condenser unit are spotless.
6. Restore power and run a test cycle.
7. If F03 persists, sealed-system diagnosis is required — schedule certified service.
8. Document model/serial and approximate age — many Bosch heat-pump dryers have extended sealed-system warranty coverage.

Why it happens

Typical signs: No heat on heat-pump model · Long cycle times · Cycle ends prematurely · F03 displayed soon after start

• Restricted airflow at evaporator/condenser fins Lint/dust buildup on heat exchanger restricts heat transfer.
• Pressure sensor or temperature sensor fault Sensors monitoring the sealed system are out of range.
• Refrigerant leak Sealed-system service required from certified technician.
• Failed compressor Compressor unable to maintain pressure differential.
• Ambient temperature too low Heat-pump dryers struggle below ~50°F garage installations.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

• Bosch dryer heat exchanger cleaning kit Common replacement
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