What this error means
Water level sensor fault — the machine cannot correctly detect how much water is in the drum
The E36 error means the pressure sensor — which tells the control board how much water is currently in the drum — is not functioning correctly. This is most commonly caused by a blocked or kinked pressure hose, a build-up of detergent residue inside the pressure hose or sensor chamber, or a faulty pressure sensor unit. If this fault is ignored the machine may overfill.
What you'll need first
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Step-by-step
Symptoms to look for
- Machine fills with water then pauses for an unusually long time before tumbling
- Drum appears to fill beyond the normal level — water visible high in the door glass
- Programme stops during the fill phase with E36 displayed
- Machine behaviour is erratic — fills normally sometimes, overfills or underfills other times
Diagnostic steps
Unplug the machine and hold the power button for 10 seconds to discharge the control board. Leave unplugged for 60 seconds. Plug back in and run a 40-degree programme. Observe whether the drum fills normally and the programme proceeds.
Place a spirit level on top of the machine and check it in two directions — front to back and side to side. A machine that is significantly off-level causes water to pool unevenly, giving the pressure sensor inconsistent readings. Adjust the feet by turning them anti-clockwise to raise or clockwise to lower — tighten the locking nut firmly against the machine base once level.
With the machine unplugged, remove the top panel by undoing the two screws at the rear edge and sliding the panel backwards and off. You will see a narrow plastic or rubber hose running from a small connection point on the outer drum body up to the pressure sensor — a small circular component with an electrical connector on top and the pressure hose connected to its bottom port. Inspect the full length of the hose for kinks, cracks, splits, or disconnection at either end.
Gently disconnect the pressure hose from both the drum connection and the pressure sensor by carefully pulling each end off its stub fitting. Blow gently through the full length of the hose — you should feel free, unobstructed airflow. If it feels restricted, flush it through with a small amount of warm water then dry it completely before refitting. Check the drum connection stub for limescale or detergent build-up using a cotton bud or soft brush.
With the pressure hose disconnected from the sensor, set a multimeter to resistance and test across the electrical terminals on the sensor — disconnect the wiring harness connector first. Consult the service manual or part datasheet for your specific Siemens model for the expected resistance range. A completely open circuit (OL) across all terminal combinations typically indicates a failed sensor.
Push the pressure hose firmly onto both stubs until it seats fully against the retaining shoulder at each end. Replace the top panel. Run a 40-degree programme and observe the fill — the machine should fill to the correct level, pause briefly, and begin tumbling.
When to call an engineer
- Pressure hose is cracked, split, or has collapsed or deformed internally
- Pressure sensor tests open circuit across all terminal combinations with a multimeter
- Machine overfills even after the hose has been cleared and the sensor confirmed clean
- Control board is not responding correctly to sensor signals — confirmed by correct sensor readings but continued fault
Frequently asked questions
What does the pressure sensor actually do?
Can a blocked pressure hose cause the machine to overfill?
Is E36 dangerous?
Can I inspect the pressure hose and sensor myself?
🎯 What is likely causing this fault?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
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Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| Pressure Switch | £20 - £50 | 🛒 Amazon UK → |
| Pressure Switch | £25 - £40 | 🏷️ eBay UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.