What Does Error Code E38 Mean on a Siemens Washing Machine?
Locate and manually clean the pressure chamber and its connecting hose to clear any soap residue or debris blocking the air passage — this resolves the majority of E38 faults and typically takes about 20 minutes.
Fault description
Error code E38 points to a problem with the pressure chamber, a small but important component in your Siemens washing machine's water-level sensing system. The pressure chamber works by trapping a pocket of air; as water fills the drum, the air pressure in this chamber changes, and a sensor reads those changes to tell the machine how much water is present.
When the chamber or its connecting hose becomes blocked — usually by a build-up of detergent residue, limescale, or debris — the machine can no longer accurately measure the water level. As a safety response, it stops the cycle and displays E38 to alert you that manual cleaning is needed.
You may notice the machine pausing mid-cycle, failing to fill or drain properly, or simply refusing to start a new programme. The good news is that this fault is almost always caused by a blockage you can clear yourself without specialist tools.
Causes
- Blocked pressure chamber — Over time, soap scum, detergent residue, and limescale accumulate inside the small plastic pressure chamber body. This narrows or completely seals the air passage, preventing accurate water-level readings.
- Blocked or kinked pressure hose — The narrow rubber or plastic hose connecting the pressure chamber to the drum can become clogged with residue or physically kinked. Even a partial blockage is enough to trigger E38.
- Excessive detergent use — Using too much detergent — or a non-HE (high-efficiency) detergent in a modern low-water machine — produces excess foam that can be drawn into the pressure chamber and harden over time.
- Limescale build-up in hard-water areas — In areas with hard water, limescale deposits can form inside the pressure chamber and hose, gradually restricting airflow. This is a slow process but a very common root cause.
- Faulty or damaged pressure sensor (pressostat) — If the chamber and hose are clean but the error persists, the pressure sensor itself may have failed or developed a fault. This is less common but requires component replacement.
- Damaged pressure chamber body — Physical cracks or deformation in the pressure chamber — sometimes caused by age or accidental damage during a previous repair — can prevent it from holding the air pressure needed for accurate sensing.
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. Wait at least two minutes to allow any residual electrical charge to dissipate. Never work on internal components with the machine powered.
- 2
Access the pressure chamber
On most Siemens washing machines, the pressure chamber is located near the top of the machine, accessible by removing the top panel. Undo the screws at the rear of the top panel, slide it back, and lift it off. The pressure chamber is a small round or cylindrical plastic component with a thin hose attached to it.
- 3
Disconnect and inspect the pressure hose
Carefully pull the thin hose off the pressure chamber fitting — it usually clips or pushes on. Hold it up to the light and look through it for any blockage. Blow gently through the hose; if air does not pass freely, it is blocked. Rinse it through with warm water and use a thin flexible brush or pipe cleaner to clear any residue.
- 4
Clean the pressure chamber
Unclip or unscrew the pressure chamber from its mounting bracket. Rinse it thoroughly under warm running water, gently shaking it to dislodge any internal residue. If limescale is present, soak the chamber in a solution of equal parts white vinegar and warm water for 15–20 minutes, then rinse clean. Do not use sharp tools inside the chamber as this can cause damage.
- 5
Check the hose routing for kinks
Before reassembling, trace the full length of the pressure hose from the chamber down to where it connects to the drum or tub. Straighten out any kinks or tight bends and ensure the hose is not pinched by other components. A kinked hose will cause the fault to return even after cleaning.
- 6
Reassemble and run a test cycle
Reattach the hose securely to the pressure chamber, remount the chamber in its bracket, and replace the top panel. Plug the machine back in and run a short cotton or rinse cycle to confirm the E38 error has cleared. Stay nearby for the first few minutes to check for any unusual behaviour.
- 7
Run a drum-clean cycle if the error returns
If E38 reappears after cleaning, run a dedicated drum-clean or maintenance wash at 90°C with a washing machine cleaner tablet. This can clear residue deeper in the system. If the error still persists after this, the pressure sensor or chamber itself may need replacing.
Affected models
Select your model to see its full troubleshooting page.
When to call a service technician
If you have thoroughly cleaned the pressure chamber and hose, confirmed there are no kinks, and run a maintenance wash, but the E38 error continues to appear, the fault is likely with the pressure sensor (pressostat) itself or with the main control board. These components require testing with a multimeter and, in most cases, replacement — work that goes beyond straightforward DIY.
You should also contact a service technician if you find the pressure chamber is cracked or physically damaged, if the hose connection points are broken, or if you are uncomfortable removing the top panel and working near internal wiring. A qualified technician can diagnose and resolve the fault safely.
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Frequently Asked Questions
Can I still use my washing machine while it shows error E38?
It is not advisable. When E38 is active, the machine cannot accurately measure the water level, which means it may overfill, underfill, or stop mid-cycle unpredictably. Using it in this state risks water spillage or damage to laundry. Clear the fault first before running a normal wash.
How do I find the pressure chamber on my Siemens washing machine?
On most Siemens front-loading models, the pressure chamber is accessed by removing the top panel — typically held by two or three screws at the rear. Once the panel is off, look for a small round plastic component near the top-left or top-right of the machine with a single thin hose running down toward the drum.
Will using less detergent really prevent E38 from coming back?
Yes, in many cases it will. Excess detergent is one of the leading causes of residue build-up in the pressure chamber and hose. Modern Siemens machines use very little water, so standard detergent doses are often too high. Using the minimum recommended amount — or switching to a concentrated HE detergent — significantly reduces the risk.
How long does it take to clean the pressure chamber?
The physical cleaning process takes around 20–30 minutes, including removing the top panel, cleaning the chamber and hose, and reassembling. If you need to soak the chamber in vinegar solution to remove limescale, allow an extra 20 minutes for soaking time.
Is error E38 the same as a water-level sensor fault?
They are closely related. The pressure chamber is part of the water-level sensing system, so a blocked chamber produces the same symptom as a faulty sensor — the machine cannot determine the correct water level. E38 specifically points to a blockage requiring cleaning, whereas a sensor fault would typically persist even after the chamber and hose have been thoroughly cleaned.