Bosch [E01] fault codewhat it means and how to fix it

Bosch’s stated meaning is straightforward: "When your Bosch tumble dryer has detected a blockage in the filter or heat exchanger, it will display an E01 error", and elsewhere on the same page, "The E01 error code is likely a result of a blockage in the filter area, which causes the appliance to overheat." That last clause is the important one — this is a code about heat building up because air is not moving, which is the central failure mode of the whole category. Their remedy has two halves. Clean the two-part fluff filter, in nine steps, which applies to every machine.

Then clean the heat exchanger, in eleven steps, beginning with allowing the dryer to cool and putting an absorbent cloth under the maintenance flap because residual water may leak out, and ending with flushing the unit under running water. And here is the difficulty. That procedure assumes a heat exchanger you can take out, and none of Bosch’s current machines has one. The SelfCleaning heat pump models rinse the exchanger automatically, give no user access to it, and instead of a cleaning procedure prompt CrE and ask you to run a care programme.

The one current model with a maintenance flap, the WTH85226GB, has a different job behind it: its manual has you lift out the heat exchanger cover and a filter insert, clean those, and leave the exchanger where it is — "Do not touch the fins on the heat exchanger", because they cut. So if you have opened the bottom of a new Bosch dryer looking for the removable part their website describes and found nothing resembling it, your machine is not faulty and you have not missed a catch.

1. 1

   Take the washing out and spread it. Then let the dryer cool — Bosch make this the first step of their own heat exchanger procedure.

2. 2

   Open the door, pull out the two-part fluff filter, and wipe around the filter area with a cloth to remove residual fluff.

3. 3

   Pull the two-part filter apart, open both halves, remove the fluff with a cloth and rinse away the rest under running water. Dry both halves before reassembling and refitting.

   Fit them dry. A damp filter attracts fibre and the code returns within days.
4. 4

   Look for a maintenance flap at the bottom of the machine. If there is none, you have a SelfCleaning model — skip to the care programme step rather than hunting for a part that is not there.

5. 5

   On the WTH85226GB and machines like it, follow the manual rather than the website. Bosch require the appliance to have cooled for 30 minutes with the door closed. Put a cloth under the maintenance flap for the water that drains, open the flap, open the lever for the heat exchanger cover, and pull the cover out by its handle.

   Bosch’s caution on this model: "Risk of cutting! Touching sharp edges on the heat exchanger may lead to cuts. Do not touch the fins on the heat exchanger." The exchanger is not removed on this machine.
6. 6

   Brush the cover clean with a soft brush and clear all dirt from its seal. Lift the middle tab on the insert, pull the insert out horizontally, clean it under running water and dry it, then wipe the opening with a soft, damp cloth. Push the insert back in horizontally until the tab clicks, refit the cover by its handle, close the lever and close the flap.

7. 7

   Only on an older machine whose own manual describes a removable heat exchanger: Bosch UK’s website procedure applies — cloth beneath the flap, open it fully, turn both levers towards each other, remove the top cap and lift the exchanger out, flush water through it from all sides, clear the seals, let it drip, refit exchanger then cap, turn the levers back and press the flap until it clicks. Bosch are explicit: only water, and no hard or sharp-edged objects to remove fluff.

8. 8

   On a SelfCleaning model, run the appliance care programme instead — the machine prompts this with CrE or CArE and it is the designed equivalent of the manual clean.