Step-by-Step DIY Fix Guide
- SAFETY: Do not open the washer door while the machine is actively de-sudsing.
- Let the cycle continue — machine auto-rinses foam.
- Add fabric softener mixture to compartment II (1 tbsp softener + 2 cups water).
- Reduce detergent for the next load.
- Switch to HE-certified detergent.
If the warning comes back after restart
- If the door closes normally but the warning keeps returning, the latch or switch path becomes more likely than a simple alignment issue.
- If airflow still seems weak after the basic checks, the fan path or a deeper obstruction becomes more likely.
- If the warning returns immediately after a clean restart, the sensor or wiring path becomes more likely than a one-time glitch.
What This Error Means
F33 on your Bosch washing machine means: Same fault as E33 — excess foam on F-code model variants. The machine detects this condition via its sensors and stops the current cycle to prevent further damage. The error will remain until the underlying cause is resolved.
The most frequent cause is too much detergent. Work through the causes listed below in order — the first cause is the most likely and the most straightforward to check.
Error F33 is DIY-safe for most homeowners. The fix typically takes under 30 minutes and requires no specialist tools. Follow the steps below exactly — skipping steps is the most common reason the error returns.
You may see suds visible through the door glass or foam escaping from the detergent drawer. Do not stop the cycle — let the machine rinse the foam out automatically.
Most Likely Cause by Symptom
The Bosch washing machine may stop, pause, or refuse to complete the cycle normally.
Likely cause: Too much detergent
Check first: SAFETY: Do not open the washer door while the machine is actively de-sudsing.
Excess foam or detergent residue may be visible.
Likely cause: Non-HE formula
Check first: Let the cycle continue — machine auto-rinses foam.
The appliance may fail to start because the door or lock state cannot be confirmed.
Likely cause: Old detergent
Check first: Add fabric softener mixture to compartment II (1 tbsp softener + 2 cups water).
Common Causes
- Too much detergent
- Non-HE formula
- Old detergent
- Light load with full dose
What Not to Do
- Do not stop the cycle
- Do not add more detergent
Model and Display Variation Notes
Model-family notes
- Bosch washing machine display wording and code formats can vary by series.
- If your model behaves differently, check the owner manual before trying any deeper maintenance step.
Display and panel differences
- Panel wording can vary by series, so confirm the exact code pattern before buying parts.
Parts, Tools and Service Options
Manual and model check
Check your exact model and manual before ordering any Bosch washing machine parts.
This section stays model-first because exact manual and parts matching matters more than a generic replacement suggestion here.
When Not to Keep Troubleshooting
F33 with correct detergent — foam sensor issue
How to Prevent It Recurring
- Use HE detergent at correct dose
Related Error Codes
E33
The washing machine has detected detergent foam overflowing from the detergent drawer, caused by too much detergent or an old detergent formula.
Foam/Bubbles Icon
The washing machine has detected too much foam inside the drum, usually caused by too much or the wrong type of detergent.
E:30 / -20
The machine has detected excessive foam in the drum, or additional water was introduced mid-cycle, causing an abnormal water level reading.
Extra notes
- This page is based on Bosch support material and stays conservative where model-specific guidance may vary.
- The goal is to help you identify safe first checks before you move into parts, service, or model-specific manual lookup.
Source and model notes
Last reviewed: 2026-04-07
Based on: Based on Bosch support material and edited into consumer-safe guidance for the exact code family on this page.
Model coverage note: Bosch washing machine code meanings can vary by series, control panel, and model family, so use this page as a safe starting point rather than a replacement for the model-specific manual.
Important: FixThisError is an independent guide, not the manufacturer. Use your model-specific manual when the panel wording or behavior differs.
Always disconnect power before inspecting appliances. If unsure, contact a licensed appliance technician.