Bosch Washer Not Draining — How to Fix It

What Does This Error Mean?

If your Bosch washer has water sitting in the drum after a cycle, the drain pump filter is almost certainly blocked — this is the most common cause. The filter is behind a small access panel at the front bottom of the machine. Open it, drain the water with a towel and the emergency drain tube, then unscrew and clean the filter. Also check the drain hose at the back is not kinked or pressed against the wall.

Affected Models

Bosch Series 2 Washer
Bosch Series 4 Washer
Bosch Series 6 Washer
Bosch Series 8 Washer
Bosch i-DOS Washer

Common Causes

Drain pump filter blocked by coins, hairpins, or lint build-up — the most common cause
Drain hose kinked behind the machine or pressed against the wall
Drain hose pushed too far into the standpipe (more than 15 cm) — causes siphoning issues
Drain pump impeller jammed by a foreign object passing through the filter
House drain blocked — the water cannot exit into the plumbing even if the pump is working

How to Fix It

Locate and open the drain pump filter access panel

At the front bottom of the machine there is a small panel (push-open or with a screw). Place a shallow tray and thick towels on the floor — water will spill when you open the filter. Some models have a small emergency drain tube alongside the filter.
Use the emergency drain tube if present

Pull out the small rubber tube next to the filter cap. Remove its plug and hold it into the tray to drain the water slowly. This drains most of the water before you unscrew the filter cap.
Clean the drain pump filter

Unscrew the filter cap anti-clockwise (it will be tight). Remove it completely and pull out the filter. Clear lint, coins, buttons, or hairpins from the filter and from the pump housing behind it. Rinse the filter under a tap.
Check the drain hose

Pull the machine away from the wall and inspect the drain hose. Check for kinks or sharp bends. The hose must be inserted no more than 15 cm into the standpipe and must loop up to at least 60 cm from the floor before going into the drain.
Run a drain cycle

Refit the filter (tighten firmly), close the access panel, and select a Drain or Spin programme. Listen for the pump to run — it makes a steady hum. If the pump runs but water stays in the drum, the pump impeller is damaged and needs replacing.

When to Call a Professional

If the filter is clean, the hose is correctly routed, but E18 or E03 is showing and the pump still does not drain, the pump motor has failed. A Bosch technician can replace the drain pump in about an hour.

Frequently Asked Questions

Bosch washer shows E18 and won't drain — what does E18 mean?

E18 on a Bosch washer means the drain pump timed out — it ran but could not clear the water in time. Clean the drain pump filter — this resolves E18 in the vast majority of cases.

Water drains very slowly from my Bosch washer — is it a partial blockage?

Yes — a partially blocked filter allows some water through but the pump cannot keep up. Clean the filter completely. Also check the drain hose is elevated correctly — a hose lying on the floor allows water to drain back by gravity.

Found a coin in the Bosch washer drain pump filter — is the pump damaged?

Coins frequently enter the pump filter without causing damage, as the filter is designed to catch them. Run a test cycle after removing the coin. If the pump drains normally, no damage was done.