Bosch Washer E01 Error — Detergent Dispenser Fix

What it means

Bosch washer E01 error indicates a problem with the detergent dispenser system — typically the inlet hose filter is clogged, the detergent drawer is blocked with congealed detergent, or water isn't reaching the drawer correctly.
The cycle stops because the wash can't proceed without detergent flushing into the drum.

Affected Models

Bosch Serie 2 / Serie 4 / Serie 6 / Serie 8 washing machines
Bosch Logixx, Maxx, Classixx ranges (older naming)
Bosch WAW, WAT, WAY, WAQ model series
Bosch Varioperfect washers
Same codes appear on Siemens and Neff washers (shared platform)

Common Causes

Inlet hose filter (mesh screen) blocked with limescale or grit
Detergent drawer crusted with old detergent and softener
Drawer housing blocked — water can't flow through
Inlet valve faulty (mechanical failure)
Water tap partially closed reducing pressure

How to Fix It

Clean the detergent drawer.

Pull the drawer all the way out (most Bosch drawers have a release lever or simply pull firmly).
Soak in warm soapy water for 15 minutes and scrub with an old toothbrush.
Rinse and refit.
Detergent build-up is the most common single E01 cause.
Clean the drawer housing.

With the drawer out, look up into the housing.
Use a small brush to clean any visible detergent crust off the back wall and the small water jets at the top.
Wipe out the bottom of the housing.
Clean the inlet hose mesh filter.

Turn off the water tap and unscrew the inlet hose from the back of the machine.
Inside the connection port is a small mesh filter — pull it out with pliers, rinse under running water, refit.
These filters block gradually over years of use and trigger E01.
Check water tap and pressure.

Make sure the water tap behind the machine is fully open.
If pressure feels low at other taps too, the household supply is the issue — contact your water supplier.

When to Call a Professional

Most E01 cases clear with a thorough clean of the drawer and the inlet filter — both owner-doable.
Only call a technician if cleaning doesn't resolve E01 and the fault persists with a known-good water supply.

Frequently Asked Questions

Why does Bosch washer E01 happen even after I clean the drawer?

Because there are usually two blockages working together — the drawer itself plus the inlet hose filter behind it.
Cleaning just the drawer often doesn't fully restore water flow if the filter is also clogged.
Always do both at the same time: clean the drawer thoroughly AND remove and rinse the mesh filter inside the inlet hose connection at the back of the machine.