What Does Error Code E38 Mean on a Bosch Washing Machine?
Locate the pressure chamber and its connecting hose at the base of the machine, detach the hose, blow gently through it to clear any blockage, and reattach it before restarting the cycle — this resolves the majority of E38 faults (takes about 15 minutes).
Fault description
Error code E38 means your Bosch washing machine has detected a problem with the pressure chamber — a small component that monitors how much water is in the drum. When this chamber or its connecting hose becomes blocked with detergent residue, limescale, or debris, the pressure sensor cannot read water levels correctly, and the machine halts the cycle to prevent overfilling or running dry.
When E38 appears, the wash cycle will typically stop mid-programme and the machine may refuse to start a new cycle until the fault is cleared. You may also notice the drum failing to fill or drain as expected. In most cases, this is a straightforward maintenance issue that does not require replacement parts — just a careful clean of the affected components.
Causes
- Blocked pressure chamber — Over time, soap scum, limescale, and fine debris accumulate inside the small plastic pressure chamber itself, restricting airflow. This is the most common cause of E38 and is resolved by manual cleaning.
- Kinked or clogged pressure hose — The narrow rubber or plastic hose connecting the pressure chamber to the pressure sensor can become kinked, pinched, or partially blocked with residue. Even a small obstruction is enough to cause a false reading and trigger E38.
- Detergent or limescale build-up in the drum sump area — Heavy detergent use or hard water can cause deposits to migrate into the lower parts of the machine, including the pressure system inlet. Using too much detergent consistently accelerates this build-up.
- Faulty or contaminated pressure sensor — If the pressure chamber and hose are both clear but E38 persists, the pressure sensor itself may be faulty or have residue on its membrane. This is less common but does occur on older machines.
- Damaged pressure chamber or hose — Physical cracks or splits in the pressure chamber body or connecting hose will cause air to escape, giving the sensor incorrect readings. Inspect both components carefully for any visible damage during cleaning.
Step-by-Step Fix
- 1
Switch off and unplug the machine
Turn the programme dial to off and unplug the washing machine from the mains socket before doing anything else. This is essential for safety whenever you are accessing internal components. Wait at least two minutes before proceeding.
- 2
Access the pressure chamber
The pressure chamber is typically located near the top or side of the outer drum, connected by a thin hose running up from the drum. On most Bosch models you will need to remove the top panel — unscrew the two or three screws at the rear of the top panel and slide it back to lift it off. Consult your model's service diagram if you are unsure of the exact location.
- 3
Detach and inspect the pressure hose
Carefully pull the pressure hose free from both the chamber and the sensor connections — it usually clips or pushes on without any tools. Hold it up to the light and look through it for any visible blockage. Run warm water through it or use a thin, soft brush to clear any residue inside.
- 4
Clean the pressure chamber
Remove the pressure chamber from its mounting — it is usually held by a single clip or screw. Rinse it thoroughly under warm running water, using a small brush to dislodge any compacted residue inside the chamber cavity. Blow gently through the inlet port to confirm airflow is completely clear before refitting.
- 5
Check for kinks or cracks
With the hose and chamber removed, inspect both carefully for cracks, splits, or areas where the hose has been pinched against another component. A cracked chamber or split hose will need to be replaced rather than cleaned. Even a hairline crack can cause persistent E38 errors.
- 6
Reassemble and run a test cycle
Reattach the hose securely to both the chamber and the sensor, refit the chamber in its mounting, and replace the top panel. Plug the machine back in and run a short cotton cycle or a drum-clean programme to confirm the error has cleared. Watch the first few minutes to ensure the machine fills and progresses normally.
- 7
Run a maintenance wash if the error clears
Once the machine is working again, run a 60°C or 90°C empty cycle with a washing machine cleaner or a cup of white vinegar. This helps dissolve any remaining residue in the drum and pressure system, reducing the chance of E38 returning in the near future.
Affected models
Select your model to see its full troubleshooting page.
When to call a service technician
If you have cleaned the pressure chamber and hose thoroughly, confirmed there are no cracks or kinks, and the E38 error still returns after a test cycle, the pressure sensor itself is likely faulty. Replacing the pressure sensor involves disconnecting electrical connectors and working close to the control board, which carries a risk of further damage if you are not confident with appliance electrics.
You should also contact a service technician if you find the pressure chamber is cracked or the hose connection points are broken and you are not comfortable sourcing and fitting replacement parts yourself, or if the error is accompanied by water leaking from the lower section of the machine, which may indicate a more serious fault.
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Frequently Asked Questions
Can I still use my Bosch washing machine while it shows E38?
No — when E38 is active the machine will not complete a wash cycle because it cannot reliably monitor the water level. Running it in this state risks overfilling or running the drum without enough water, which can damage the drum bearings or heating element. Clear the fault before using the machine again.
How long does it take to clean the pressure chamber on a Bosch washing machine?
For most homeowners, removing the top panel, cleaning the chamber and hose, and reassembling takes around 15 to 30 minutes. Having a small bowl, a soft brush, and a towel to hand will make the job quicker and tidier.
Why does my Bosch washing machine keep getting E38 after I have already cleaned it?
If E38 returns repeatedly after cleaning, the most likely causes are a hairline crack in the pressure chamber that is hard to spot visually, a pressure sensor that is beginning to fail, or persistent heavy detergent use that is re-blocking the system quickly. Try replacing the pressure hose and chamber first, as these are inexpensive parts, before moving on to the sensor.
Is E38 the same fault as E36 or E37 on Bosch machines?
They are related but distinct. E36 and E37 also involve the pressure sensing system but typically point to sensor signal faults or wiring issues rather than a physical blockage. E38 specifically indicates the pressure chamber is obstructed and requires manual cleaning as the first step.
Do I need any special tools to fix a Bosch E38 error?
In most cases you only need a Torx or Phillips screwdriver to remove the top panel, and a small soft brush for cleaning. No specialist tools are required. Having a smartphone or tablet nearby to reference your model's layout diagram can be very helpful if you are unfamiliar with the internal layout.