E03 Moderate Easy DIY

Bosch Dryer E03 — Condenser / Lint Filter Blockage

Bosch Dryer · Error code E03

What E03 Means

On condenser and heat-pump dryers, this signals reduced airflow caused by a clogged lint filter or blocked condenser unit. Dryer may run but takes excessively long or shuts down early.

Symptoms

  • Cycles take much longer than normal
  • Clothes still damp at end of cycle
  • Filter cleaning icon flashing
  • Dryer overheats or stops mid-cycle

Common Causes

1
Lint filter (primary and fine mesh) clogged

Fluff buildup restricts airflow through the heat exchanger.

2
Condenser unit fouled with lint

The slide-out condenser at the bottom needs rinsing periodically — usually every 50-100 cycles.

3
Heat exchanger fins blocked

Behind the condenser, secondary fins can hold a lint mat that requires rinsing or brushing.

4
Evaporator (heat pump models) coated in dust

Reduces heat transfer and triggers airflow alarms.

5
Blocked air channel between drum and condenser

Lint accumulates in the duct over years even with filters cleaned.

How to Fix It

  1. Open the door and remove both lint filters from the door frame — rinse under warm water until fully clean, then air dry.
  2. On condenser/heat-pump models, open the lower kickplate and pull out the condenser unit.
  3. Rinse the condenser under a faucet from both sides until water runs clear; let it drain fully before reinstalling.
  4. Inspect the condenser cavity for stuck lint and wipe out with a damp cloth.
  5. On heat-pump models, vacuum the evaporator fins gently with a soft brush attachment.
  6. Reinstall all components and close the kickplate firmly until it latches.
  7. Run a timed cycle to confirm the code clears and drying time returns to normal.

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.

More Bosch Dryer Codes

All Bosch codes → All dryer codes →

Verified against manufacturer documentation: bosch-home.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.