The reading in two sentences
Read E28 as this: there is a problem with the flow sensor. The machine may still fill using a fallback timing, so it can often be used while the fault waits for attention. You can settle whether this is a one-off or a real fault yourself; naming the failed part is not owner work.
Error codes
Reference| Code | Meaning |
|---|---|
| E28 | These error codes indicate there is an issue with the flow sensor. |
What else is happening when this shows
- The code appears while the machine still fills and washes — Measurement faults often leave the function working, which is what makes them easy to live with briefly.
- You can hear the valve open with little water arriving — That separates a commanded valve from a supplied one, which is the whole question here.
- NEAR MISS — water arrives but the cycle stops anyway — That points at level sensing rather than supply, and that is a different code.
What triggers E28, most likely first
- Grit or scale in the sensor, often after plumbing work — It goes first because it is the commonest and it points outward: the sensor sits behind the inlet where debris from the supply collects, and anything that disturbs the pipework sends grit straight to it.
- Low or fluctuating supply pressure — A sensor reading a flow that keeps changing reports an implausible measurement, so a supply problem presents as a sensor fault.
- A safety device that has shut the water off — Last: where the appliance has a supply-side protection device, it stops the water deliberately, and the code is then the consequence rather than the fault.
The order to work through
- Ask whether any plumbing work has been done recently — Grit stirred into the supply lands at the first restriction it meets, which is often this sensor.
- Open the tap fully and check the inlet hose is straight — A restricted feed makes the measurement implausible, and both checks are free.
- Open the supply tap fully and check it by hand — The cheapest possible cause and the one most often found: a tap left part closed after other work.
- Body: Compare the appliance against the house before touching either: a nearby tap answers in seconds whether this is a supply problem at all.
The reset and the checks that follow it
- Open the supply tap fully — Turn it to its stop, then run the cycle again. This alone resolves a sizeable share of fill codes.
About 5 min
- Open the tap fully, straighten the inlet hose, then power-cycle and run one short programme — You are removing the supply-side explanations before anyone opens the machine.
About 45 min
- Straighten the inlet hose behind the appliance — Pull the appliance out far enough to see the whole run rather than reaching round blind.
About 15 min
- STOP HERE — the filter screen and the valve are service items — Both mean disconnecting water and opening the appliance, so this is where an owner check ends.
Before a panel comes off
Safety
Unplug the machine or switch off its breaker before any panel comes off — a capacitor can hold a charge after the power is off. Close the supply tap before touching a hose, expect standing water when a filter comes out, and never work round the door interlock.
Where an owner check ends
Call at once if water is escaping anywhere, if a supply-side safety device has triggered, or if the appliance fills when it should not.
Other codes on a Bosch washing machine
What is deliberately not here
Treat this as the general Bosch washing machine reading. It stops short of anything model-specific — part numbers, harness colours, connector layouts and service-mode entry — because those differ by family and a technician takes them from the rating plate rather than from a code. A family- or model-specific page, where one exists, is linked from the code index below and is the closer answer.
Links: - [Bosch washing machine error codes](/blog/bosch-washer-error-codes)
Next steps
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
