What E64 means on your Bosch dryer
Error code E64 is specific to Bosch heat pump dryers. It indicates that the heat pump refrigerant circuit is underperforming — the temperature differential between the evaporator (cold side) and condenser (hot side) is below the expected range. This means the heat pump cannot efficiently extract moisture from clothes.
Symptoms
- Drying takes much longer than expected
- Clothes remain damp even after extended cycles
- The dryer runs but doesn’t produce adequate warmth
- E64 appears during operation, usually after 10–20 minutes
Common causes
- Clogged condenser filter — the heat exchanger filter is packed with lint, severely reducing airflow across the condenser and evaporator coils
- Refrigerant leak — a leak in the sealed circuit reduces the refrigerant charge below the operating minimum
- Compressor failure — the heat pump compressor loses efficiency or fails entirely
- Blocked evaporator — lint bypasses the filter and coats the evaporator fins, insulating them
Troubleshooting steps you can try
- Clean the condenser filter — open the lower access panel, remove the filter, and rinse under running water. This is the most common cause and often resolves E64.
- Clean the heat exchanger — with the filter removed, use a vacuum with a narrow nozzle to clean lint from the visible condenser and evaporator surfaces.
- Clean the door lint filter — a heavily clogged door filter pushes excess lint toward the heat exchanger.
When to call a technician
If thorough cleaning doesn’t resolve E64, the refrigerant circuit has a fault — either a leak or a compressor issue. This requires a technician with refrigerant handling equipment. Heat pump compressor replacement is one of the most expensive dryer repairs. For dryers out of warranty, compare the repair cost against replacement cost. Codes may vary by model generation and series.
Need help? Schedule Bosch Dryer repair with a certified technician, or contact our team for a free diagnosis consultation.
