What Does Error Code E45 Mean on a Bosch Washing Machine?
Power cycle the machine by switching it off at the wall socket, waiting 5 minutes, then switching it back on and starting a new programme — this clears temporary communication errors in the control module and restores normal operation in many cases (takes about 5 minutes).
Fault description
Error code E45 points to a breakdown in communication within your Bosch washing machine's electronic control system. The control module — sometimes called the PCB or main board — is responsible for coordinating every part of the machine, from the motor and drum to the door lock and water valves. When it loses reliable contact with one or more of these components, it logs E45 and halts the programme to prevent further damage.
When this error appears, the machine will typically stop mid-cycle or refuse to start a new one. The display shows E45 and the drum will not rotate. In some cases the door may remain locked. The fault can be a one-off electronic glitch, but it can also point to a wiring problem or a failing component that will need closer inspection.
Causes
- Temporary control module glitch — A brief power fluctuation or software hiccup can cause the control module to lose communication with other components. This is the most common cause and often clears itself after a full power reset.
- Loose or damaged wiring harness — The wiring loom connecting the control module to the motor, door lock, or other sub-components can work loose over time due to vibration. A damaged or corroded connector will interrupt the data signal and trigger E45.
- Faulty door lock assembly — The door interlock sends a signal back to the control module confirming the door is secure before a cycle begins. If the lock mechanism is worn or its wiring is damaged, the module may register a communication failure.
- Failing motor control board — Some Bosch models use a separate motor control board that communicates with the main PCB. If this secondary board develops a fault, the main module cannot receive motor feedback and will display E45.
- Defective main control module (PCB) — If the main PCB itself has suffered component failure — often caused by a power surge or moisture ingress — it may be unable to maintain communication with the rest of the machine. This is less common but requires board replacement or professional repair.
Step-by-Step Fix
- 1
Power cycle the machine
Turn the washing machine off using the programme dial, then switch it off at the wall socket. Leave it unplugged for at least 5 minutes to allow the control module to fully discharge and reset. Plug it back in, select a short programme, and see if the error returns.
- 2
Check the door is fully closed and latching
Open and firmly close the door, making sure you hear a clear click from the lock. A door that appears closed but has not engaged the latch properly can prevent the control module from receiving the door-locked signal. Try starting the machine again after re-closing the door.
- 3
Inspect the door lock wiring
With the machine unplugged, carefully remove the door seal lip and the front panel trim to access the door lock assembly. Check that the wiring connector is firmly seated on the lock and that no wires are visibly pinched, burnt, or corroded. Reseat any loose connectors and reassemble before testing.
- 4
Check the wiring harness connections at the control module
The main PCB is usually located behind the top panel or the rear panel depending on your model. With the machine unplugged, remove the relevant panel and locate the control board. Gently press each wiring connector firmly into its socket — vibration from normal use can cause them to work loose over months or years.
- 5
Inspect wiring for visible damage
While you have access to the internal wiring, run your eye along the main harness looking for chafed insulation, burn marks, or broken wires. Pay particular attention to areas where the harness passes near the drum or motor, as these are high-vibration zones. Any damaged section of wiring will need to be repaired or the harness replaced.
- 6
Test the door lock assembly
If you have a multimeter, you can test the door lock for continuity across its terminals — consult your model's wiring diagram for the correct values. A lock that shows no continuity when engaged is faulty and should be replaced. Replacement door locks for Bosch machines are widely available and are a straightforward swap.
- 7
Consider the motor control board or main PCB
If all wiring and components check out but E45 persists, the fault likely lies with the motor control board or the main PCB itself. At this stage, further diagnosis requires specialist equipment and knowledge of electronic components, so this is the point to contact a service technician.
Affected models
Select your model to see its full troubleshooting page.
When to call a service technician
If the error code returns immediately after a power reset, and you have already checked all accessible wiring connections without finding anything loose or damaged, the fault is likely inside the control module or motor control board itself. These components require specialist diagnostic tools to test properly and are not straightforward to replace without experience.
You should also call a service technician if you notice any burn marks, a smell of burning plastic, or signs of moisture around the PCB area. These are signs of more serious electrical damage that should not be investigated further without professional training.
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Frequently Asked Questions
Can I still use my Bosch washing machine while it shows E45?
No — when E45 is active the machine will not complete a cycle and may not start at all. Attempting to force it through a programme is unlikely to work and could mask a wiring fault that gets worse over time. Resolve the error before using the machine again.
Will a power reset always fix error code E45?
A power reset fixes E45 when the cause is a temporary software glitch or a minor voltage fluctuation. If the error comes back after the reset, there is an underlying hardware fault — a loose connector, a faulty door lock, or a failing board — that needs to be investigated further.
How much does it cost to replace a Bosch washing machine PCB?
Main control boards for Bosch washing machines typically cost between £60 and £180 for the part alone, depending on the model. Labour from a service technician will add to this. It is worth getting a quote before committing, as on older machines the repair cost can approach the value of the appliance.
Is E45 the same as other communication error codes on Bosch machines?
Bosch uses several communication-related error codes, and E45 specifically relates to a fault in the control module's communication with other components. Other codes such as E44 or E46 point to different aspects of the control system. Always check the exact code displayed before starting any diagnosis.
How do I find my Bosch washing machine model number?
The model number is printed on a sticker inside the door frame — open the door and look around the inner rim. It usually starts with letters such as WAT, WAN, or WGB followed by a string of numbers. You will need this number to order the correct replacement parts for your machine.