Bosch Washer Error Codes: What They Mean and How to Fix Them

Last updated: October 5, 2026 · Applies to Bosch 300, 500 and 800 Series compact front-load washers sold in the US (older models show F-codes instead of E-codes; Nexxt models differ) · Sources

Bosch compact washers show codes like E:18 (or F18 on older models) — and most of the common ones come down to the drain pump, the water supply or the door. This guide covers 8 Bosch washer codes, including Bosch’s own drain pump cleaning procedure.

Bosch washer error code table

Always turn the washer off and unplug it before opening the service flap or removing hoses. Drained water may be hot.

Don’t see your code? Search your E-Nr on Bosch’s US support site for the owner’s manual and code list.

Troubleshooting without an error code

No code on the display, but something’s not right? Work through these safe checks for the most common washer problems, in order. They apply to most Bosch washers. Unplug the washer before touching hoses, filters or panels.

Washer won’t start

1. Check the plug is fully seated in a working outlet and the breaker hasn’t tripped (test the outlet with a lamp).
2. Close the door or lid firmly — the washer won’t start if it can’t detect it as closed.
3. Look for a lock icon or “CL/LOC” on the display: Child/Control Lock may be on. See your manual for which button to hold.
4. Make sure you pressed Start (on many models you must select a cycle and then press and hold Start, or press Start within a few seconds of powering on).

Washer won’t drain or clothes are soaking wet

1. Cancel the cycle and run a Drain & Spin (or Rinse & Spin) to see whether it drains at all.
2. Check the drain hose behind the washer for kinks or a crushed section, especially after the washer was moved.
3. Make sure the drain hose isn’t pushed too far into the standpipe and isn’t sealed into it with tape — this can cause siphoning or slow draining.
4. If your washer has a drain pump filter or coin trap, unplug the washer and clean it (towels and a shallow pan ready; the water may be hot). On Bosch compact washers the drain pump is behind the service flap at the bottom front, with an emergency drain hose.
5. Too many suds can stop a washer draining and spinning properly — use HE detergent and measure it.

Washer won’t spin

1. Open the door or lid and spread the load evenly; add a couple of towels to a single heavy item or remove a few items from an overloaded drum.
2. Make sure the washer has drained — most washers won’t spin with water in the tub (see “won’t drain”).
3. Check the washer is level and doesn’t rock; adjust the feet.
4. Check the door or lid is fully latched — spin requires it to lock.
5. Run a Spin-only cycle on its own to test.

Washer is leaking

1. Unplug the washer and turn off both water taps before investigating.
2. Check the fill hose connections at the taps and at the back of the washer; hand-tighten loose couplings and replace cracked or bulging hoses.
3. Check the drain hose is secured in the standpipe and the standpipe isn’t overflowing.
4. On front-loaders, look for tears or trapped items in the door gasket and check that the drain pump filter cap is screwed in fully.
5. Too many suds can push water out of the dispenser or door — use HE detergent at the recommended dose.
6. If water is coming from underneath with no obvious source, stop using the washer and call a technician.

Washer is noisy, shaking or “walking”

1. Rebalance the load and avoid washing a single heavy item on its own.
2. Level the washer: adjust the feet until it doesn’t rock and tighten the lock nuts if fitted.
3. On a new washer, confirm the shipping bolts or transit restraints were removed (see the installation guide).
4. Check pockets for coins, keys and other hard objects; on models with a drain pump filter, a rattling or grinding sound while draining can mean an object in the filter.
5. Loud banging, grinding or squealing that continues with an empty drum needs a technician.

Washer smells musty

1. Run the washer’s cleaning cycle (Tub Clean, Clean Washer, Self Clean or similar) with an approved washer cleaner or bleach as your manual directs.
2. On front-loaders, wipe the door gasket — including the folds — and leave the door ajar between loads so the drum can dry.
3. Remove and rinse the detergent dispenser drawer and clean the drawer cavity.
4. Clean the drain pump filter if your model has one; trapped lint and debris can smell.
5. Use only HE detergent and don’t overdose — excess detergent and fabric softener leave residue that feeds odors.

Common mistakes

Many “faults” are caused by how the washer is loaded, installed or maintained. Avoid these and you’ll see far fewer codes:

• Overloading the drum. Clothes need room to move. Packing the drum causes unbalanced loads, poor rinsing and strain on the motor and suspension.
• Too much detergent, or the wrong kind. Modern washers use little water. Use HE (high-efficiency) detergent and measure it — excess suds can cause drain, spin and suds codes, leaks and odors.
• Washing one heavy item alone. A single bath mat, rug or comforter bunches to one side. Add a few similar items to balance it, or use the bulky/bedding cycle.
• Ignoring the drain hose. A kinked hose, or one pushed too far into the standpipe or taped in place, causes slow draining or siphoning.
• Leaving taps half-closed. Partly open taps and dirty inlet screens cause slow-fill codes. Open both taps fully.
• Never cleaning the washer. Skipping the cleaning cycle, gasket wipe-downs and filter cleaning leads to odors, residue and drain problems.
• Resetting instead of fixing. Unplugging clears the display but not the cause. Do the checks first; repeated resets can also clear the fault history a technician would use.

Tips and tricks for Bosch owners

Useful Bosch-specific features and procedures, confirmed from Bosch’s own support pages and manuals. Exact buttons vary by model, so check your manual.

• Clean the drain pump the Bosch way. Unplug, open the service flap, drain into a pan with the emergency hose, unscrew the pump cover, clear debris and check the impeller turns. After refitting, pour about a quart of water into the dispenser and check for leaks before running Drain.
• Don’t immerse an AquaStop hose. Bosch’s AquaStop hose contains an electric safety valve — never submerge the housing in water.
• Check the flow rate for E:17. Bosch says the tap should deliver about 2.5 gallons (10 liters) per minute. Fill a bucket for a minute to test.
• F-codes = E-codes. Older Bosch washers show F18 where newer ones show E:18 — same fault.
• Mix large and small items. Bosch recommends mixing large and small items to reduce imbalance.

Safety note

When to call a pro

The steps above are limited to safe, user-level checks. Call Bosch service (1-800-944-2904) or a qualified appliance technician if:

• E:23 / F23 (AquaStop) appears — there’s a leak inside the washer.
• E:18 returns after the pump is clean and the hose is clear.
• The door stays locked with water inside and won’t drain.
• Water leaks from underneath and you can’t find a loose hose.
• You notice a burning smell, smoke, sparks or loud grinding or banging.

Frequently asked questions

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