E33
Bosch Washing Machine
Severity: ModerateWhat Does This Error Mean?
Error code E33 on a Bosch washer means the control board and the pressure switch (water level sensor) are giving conflicting information. The pressure switch tells the board how much water is in the drum. If the board's reading does not match what the pressure switch is reporting, E33 is set. This usually means the pressure switch is faulty, the pressure hose is kinked, or the control board has an issue. Your washer may stop filling, overfill, or stop mid-cycle.
Affected Models
- Bosch Front-Load Washers
- Bosch Serie 4 washers
- Bosch Serie 6 washers
- Bosch Serie 8 washers
- Bosch WAx series models
Common Causes
- A faulty pressure switch giving inaccurate water level readings
- A kinked or blocked pressure hose connecting the tub to the pressure switch
- Detergent residue or debris clogging the pressure hose or switch port
- A failed main control board not correctly interpreting the pressure switch signal
- A loose connector at the pressure switch or control board
How to Fix It
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Perform a hard reset. Unplug the washer for 10 minutes and plug it back in. A transient signal mismatch between the board and pressure switch sometimes clears after a full power cycle.
Run a short cycle immediately after the reset to see if E33 returns.
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Locate the pressure hose. It is a thin, flexible tube that runs from the bottom of the drum tub to the pressure switch. Inspect it for kinks, cracks, or blockages. A kinked hose cannot transmit accurate pressure to the switch.
The pressure hose is usually found by removing the top panel of the washer.
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Disconnect the pressure hose from both ends and blow through it gently. If it is blocked, clean it with warm water. Also blow into the pressure port at the bottom of the tub to clear any detergent residue that may have clogged the opening.
Soap residue blocking the pressure port is a common cause of E33, especially in washers used with excessive detergent.
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Check the wire connector at the pressure switch. Make sure it is fully seated and free of corrosion. A poor connection causes signal dropouts that the board interprets as a mismatch.
The pressure switch is typically a small round disc with a tube port and an electrical connector.
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Test the pressure switch by blowing gently into the hose port while listening for a click. A working switch clicks when pressure is applied and again when released. No click indicates the switch has failed and needs replacement.
Pressure switches cost $20-$50 online. Match the part number.
When to Call a Professional
If cleaning the pressure hose and resetting the machine do not clear E33, the pressure switch likely needs replacement. Pressure switches cost $20-$50. If the switch tests fine, the control board may have an issue — confirm this with a technician before replacing the board.
Frequently Asked Questions
What does the pressure switch do in a washing machine?
The pressure switch (also called a water level sensor) monitors how much water is in the drum. As water fills the drum, it compresses air in the pressure hose, which increases pressure at the switch. The switch sends this reading to the control board so it knows when to stop filling. Without an accurate reading, the board may underfill, overfill, or pause the cycle incorrectly.
Can overfilling cause E33?
Yes — if the pressure switch is stuck open (reporting no water) while the drum is full, the board keeps filling the machine, which can lead to overfilling. Conversely, if it is stuck closed (reporting full when empty), the board stops filling before enough water enters the drum. Both conditions create a mismatch that can set E33.
How much does it cost to fix E33?
Cleaning the pressure hose: free. A pressure switch replacement: $20-$50 for parts, $80-$150 with labor. A control board replacement (if confirmed faulty): $150-$400 for parts. Technician diagnosis: $80-$150.