Bosch Washer E37 Error Code - Causes & Fix

Bosch Washer E37 Error Code — What It Means

E37 on a Bosch washer indicates an overfilling or pressure-sensing fault. The control board has detected a water level that does not match what it expected, usually because the pressure switch or sensor is sending an incorrect signal, the pressure chamber or air trap is blocked, or an inlet valve is not closing fully. In practical terms, the machine believes the tub is filling too much or cannot accurately read the true fill level because something in the pressure circuit is not working correctly.

It is important to note that Bosch’s official U.S. consumer documentation does not clearly list E37, so this interpretation comes from third-party Bosch code references and should be treated as the most likely meaning rather than a Bosch-published definition. Bosch does publish codes E26/F26 and F27 for pressure sensor issues, which suggests this family of faults centers on the pressure system.

Jump to Fix

Common Causes

• Blocked pressure chamber or air trap Detergent sludge or debris inside the pressure chamber prevents the sensor from seeing the true water level.
• Faulty pressure switch or sensor The pressure sensor itself sends an incorrect reading to the control board even when the water level is normal.
• Kinked, split, or disconnected pressure hose Damage or obstruction in the sensing tube stops pressure changes from reaching the sensor.
• Inlet valve stuck open or leaking A mechanically failed valve allows water to continue filling even when the valve coil is de-energized.
• Control board misinterpreting level signals Less commonly, the main control can generate false overfill faults if its level-circuit inputs are damaged or corrupted.

Step-by-Step Fix

1. Power down the washer and unplug it, then turn off the water supply at the wall valves before beginning any inspection.
2. Check for actual overfill by opening the door (once the lock releases) or inspecting through the glass to see whether the tub is genuinely filled higher than normal or if the fault is a false reading.
3. Locate and inspect the pressure hose, which runs from the bottom of the tub (often at a small air-trap chamber) up to the pressure sensor near the control board, for kinks, splits, disconnection, or blockage.
4. Remove and clean the pressure chamber (air trap) at the tub sump by disconnecting the hose, flushing out detergent sludge or debris with warm water, and ensuring the small sensing port is completely clear.
5. Test the inlet valve by removing power, disconnecting the inlet hoses, and checking that the valve seats close fully and do not pass water when de-energized (you can blow gently through the valve to confirm it seals).
6. Test or replace the pressure sensor if the hose, chamber, and valve are all verified good, since an internal sensor fault will send the wrong signal to the control even when the physical pressure path is clear.
7. Run a rinse or short test cycle after reassembly to confirm the level system responds correctly and the E37 does not return, or power-cycle the machine and contact Bosch support if the code persists.

Parts Often Needed

When to Call a Pro

Call a qualified appliance technician if you are not comfortable disassembling the cabinet to access the pressure system, if the pressure chamber and hose are clear but the fault returns, or if you suspect the main control board. Pressure-sensor and inlet-valve diagnostics require basic multimeter skills and an understanding of the fill cycle. Because Bosch does not publish E37 in its official U.S. consumer code list, a trained Bosch service provider can confirm the exact fault definition for your model and access factory test modes and specifications not available to owners.