The short answer
Read E28 as this: the control reports an electronics fault, and the published table names no component for it. If the dryer completes a full cycle after a power cycle you can use it; stop if the code returns mid-cycle. 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 | There is an electronics fault/error. |
What the machine does alongside the code
- The code appears at power-up before a programme is chosen — That is the control finding the fault during its own start-up check.
- The cycle stops part-way with the code on the display — A self-check failing mid-cycle stops the machine rather than letting it continue.
What triggers E28, most likely first
- Heat and lint dust around the control — It goes first among the causes you can act on: a dryer control sits in a warm cabinet full of fine dust, and dust bridging a connector produces an unaccountable reading that comes and goes with how hard the machine is worked.
- A supply shared with another heavy load — The control is the most supply-sensitive part of the machine, so a shared circuit or an extension lead produces electronics readings on hardware that is perfectly sound.
- A genuinely failed control board — Last, and deliberately so: it is the most expensive answer, and the four causes above imitate it exactly while costing nothing to eliminate.
Check in this order, and why
- Clear the filter and the air paths before judging anything — A machine running hot because of restricted airflow is harder on its control than one that is not.
- Note which functions still work — A general code with one specific function missing is far easier to diagnose than a general code alone.
- Have the control connectors and harness inspected — Last, because it needs the appliance open, and because it is where a returning code leads.
- Body: Eliminate the environment before the electronics — supply quality, heat and moisture cause more of these codes than boards do.
The reset, then the owner-safe checks
- Switch the appliance off at the breaker for a full minute — A full minute so the control loses its supply completely, then restore power and watch the power-up.
About 5 min
- Power down for a full minute, clean the filter and air paths, then run one complete cycle and note the result — Whether it finishes, where it stops and what the display shows are the three things worth recording.
Tools: vacuum, soft brushAbout 60 min
- Run one ordinary cycle and note exactly what happens — Whether it completes, where it stops and what the display does are the three things worth writing down.
About 60 min
- STOP HERE — do not keep resetting a code that returns at once — A code that comes straight back is live, and resetting round it removes the evidence a technician needs.
Before anything is opened
Safety
Unplug the dryer or switch off its breaker before any panel comes off — a capacitor can hold a charge after the power is off. Never run it with the filter out or the air paths blocked, because lint is combustible. On a gas model, if you smell gas, leave the building and call the gas utility from outside without switching anything on or off.
When this is a service call rather than a reset
Call straight away if you smell hot plastic, see scorching at a connector, or the appliance behaves unpredictably rather than simply stopping.
Neighbouring codes on Bosch dryers
What this page does not cover
This reading applies to the Bosch dryer line as a whole, not to one family or model. It does not cover what differs between model lines — wiring colours, connector positions, part numbers and service-mode sequences — which are in your own model manual and which a technician matches to the rating plate rather than to this code. Where a family- or model-specific page for this code exists, it is linked from the code index below and it is the more specific answer.
Links: - [Bosch dryer error codes](/blog/bosch-dryer-error-codes)
Where to go next
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
