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Quick answer: On most Bosch front load washing machines, E23 indicates a drain pump electrical fault—the control board sent a signal to run the pump and received no response, or detected an abnormal current reading from the pump motor. Unlike E18 (which is a drainage timeout that can be caused by a blocked filter), E23 points more directly at the pump motor itself, its wiring, or the pump relay on the control board. In the majority of E23 cases, replacing the drain pump resolves the fault.
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Drain pumps for Bosch front loaders: WAW28620AU / WAW28790AU — $49.95 · WAW32640AU / WAY32891AU — $49.95 · find your model
What does Bosch E23 mean?
E23 is classified as a drain pump fault on most Bosch front load washing machines. Where E18/F18 is a drain timing fault (water did not empty in time—often caused by a blockage), E23 is an electrical or mechanical pump fault—meaning the pump motor has not responded as expected to the control board’s command.
In practical terms, this usually means one of three things: the pump motor winding has failed (open circuit or short circuit), the pump has seized and is drawing excessive current, or the pump relay on the main control board (PCB) has failed and is not supplying power to the pump at all.
It is worth noting that Bosch fault code definitions can vary slightly across model series and firmware versions. The description above reflects what is well-established for the majority of Bosch front loader models sold in Australia. Always cross-reference with the fault code list in your machine’s service documentation if available.
E23 causes and likelihood
| Cause | Likelihood | DIY repair? |
|---|---|---|
| Failed drain pump motor (open or short circuit winding) | Most common | Yes — replace pump ~$50 |
| Pump seized by a foreign object (coin, pin) | Moderate | Yes — remove obstruction or replace pump |
| Faulty pump relay on control board (PCB) | Less common | Possible — PCB replacement or repair |
| Damaged wiring harness to pump | Less common | Yes — inspect and repair connector/wiring |
How to diagnose and fix Bosch E23
- Power off and unplug the machine. Safety first. Unplug from the wall and wait two minutes.
- Check and clean the pump filter. Even though E23 is an electrical fault code, it is worth checking the filter first. A severely jammed filter can cause the pump motor to seize and draw abnormal current. The filter is behind the small access flap at the bottom front of the machine. Remove, clean, and refit.
- Listen for the pump during a drain cycle. Plug back in and start a Spin cycle. During the drain phase, listen at the front lower panel. A healthy pump produces a consistent low hum. Complete silence suggests the pump is not being powered (relay or wiring issue). A loud grinding or buzzing suggests the pump motor has seized or a winding has failed.
- Test pump resistance with a multimeter. Unplug the machine and access the pump (remove the lower front panel). Disconnect the wiring plug from the pump. Set a multimeter to resistance (ohms) mode and probe the two motor terminals. A healthy pump winding will show a low but non-zero reading—typically a few ohms. An open circuit reading (OL / infinity) means the winding has failed. A zero or near-zero reading may indicate a short. Either way, replacement is needed.
- Replace the drain pump. Match your model number from the model sticker inside the door frame to the correct pump. Available Bosch drain pumps (all $49.95):
- WAP28380AU / WAP28482AU
- WAW28420AU / WAW28441AU
- WAW28620AU / WAW28790AU
- WAW32640AU / WAY32891AU
- WGA244U0AU / WVH28490AU
Not sure which fits? Use the Part Finder.
- If the pump tests fine, check the control board. If the pump winding tests as healthy and there is no obstruction, the pump relay on the PCB may have failed. This is less common and is generally a job for a qualified technician.
E23 versus E18 — what’s the difference?
Both E18/F18 and E23 relate to the drain pump, but they are distinct faults. E18/F18 is a timeout fault—the pump ran but water did not drain fast enough, which is frequently caused by a blocked filter. E23 is an electrical pump fault—the pump motor did not respond or behaved abnormally. If you are seeing E23, cleaning the filter alone is unlikely to clear it, though it is still worth checking as a first step.
Frequently asked questions
Can E23 be caused by a blocked pump filter?
Indirectly, yes. If a severely jammed foreign object has seized the pump impeller, the pump motor may draw abnormal current and trigger E23. Checking and clearing the filter is always a worthwhile first step before replacing the pump.
My machine shows E23 but drains some water — is the pump partially working?
It is possible for a failing pump motor to drain slowly before giving up and triggering E23. Partial drainage does not necessarily mean the pump is fine—a weakening motor winding can fail progressively.
How long does it take to replace a Bosch drain pump?
Most DIY-capable repairs take 30–45 minutes. The pump is typically accessible from the front by removing the lower kick-panel, without needing to tip or disassemble the machine significantly.
Is E23 covered under the Bosch warranty?
If your machine is within the original manufacturer’s warranty period, a pump failure should be covered. Contact Bosch Australia service before replacing any parts yourself to avoid affecting your warranty coverage.
Can a power surge cause E23?
A power surge could potentially damage the pump relay on the control board, which would result in the pump not receiving power and triggering E23. If E23 appeared after a power event, the PCB relay is worth considering alongside the pump itself.
Related
Disclaimer: this article is general information only and is provided without warranty of any kind. Appliance designs vary between models and production runs — always follow the manufacturer’s instructions, switch off and unplug the appliance before starting any work, and confirm parts against the model number on your appliance’s model sticker. Any repair is undertaken at your own risk and Oz Appliance Spares accepts no liability for injury, loss or damage arising from work performed after reading this guide, to the maximum extent permitted by law. If in doubt, use a qualified technician.
