What Does Error Code E63 Mean on a Bosch Washing Machine?
Check and clean the filter, then inspect the heating element connections — unplug the machine, remove the back or front panel to access the heater wiring, reseat any loose connectors, and restart a wash cycle to see if E63 clears (takes about 15 minutes).
Fault description
Error code E63 points to a problem in your Bosch washing machine's heating circuit. This is the system responsible for warming the water to the temperature you select on the dial or display. When the machine detects that the water is not reaching the correct temperature — or that the heating components are behaving unexpectedly — it stops the cycle and displays E63 to prevent damage or unsafe operation.
When this error appears, the wash cycle will typically pause or fail to progress past the heating phase. You may notice that the drum stops turning, the programme timer freezes, or the machine drains and ends the cycle early without completing a proper wash. The water inside may feel cold even after the machine has been running for several minutes.
The fault can originate from a failed heating element, a faulty NTC temperature sensor, damaged wiring, or in some cases a problem with the main control board. Many of these causes are straightforward to diagnose at home before deciding whether professional help is needed.
Causes
- Faulty heating element — The heating element is the most common cause of E63. Over time, elements can burn out or develop an internal break, meaning they draw no current and cannot heat the water. A failed element will usually show as an open circuit when tested with a multimeter.
- Defective NTC temperature sensor — The NTC (Negative Temperature Coefficient) sensor monitors water temperature and reports back to the control board. If the sensor fails or drifts out of its calibrated range, the board may interpret the readings as a heating fault even if the element itself is working correctly.
- Loose or corroded wiring connections — The connectors linking the heating element and NTC sensor to the control board can work loose over time due to vibration, or corrode in the damp environment inside the machine. A poor connection can mimic a component failure and trigger E63.
- Limescale build-up on the heating element — In hard water areas, limescale deposits coat the heating element and reduce its efficiency. In severe cases, the element overheats locally, trips a thermal cut-out, or fails entirely, causing the control board to log a heating circuit error.
- Faulty main control board (PCB) — If the PCB cannot correctly send power to the heating circuit or read the sensor signal, it may generate a false E63 code. This is less common than element or sensor failure, but should be considered if all other components test as healthy.
Step-by-Step Fix
- 1
Power cycle the machine
Switch the machine off at the mains and unplug it. Wait at least two minutes, then plug back in and select a new programme. Occasionally a temporary control board glitch can trigger E63, and a full power reset clears it. If the code returns immediately, continue to the next steps.
- 2
Run a hot wash and observe behaviour
Select a 60°C or 90°C cotton programme and start the machine. Stay nearby for the first 10–15 minutes and check whether the drum pauses during the heating phase. If the cycle stalls at the same point every time, this confirms the fault is genuinely in the heating circuit rather than a one-off error.
- 3
Inspect and clean the pump filter
A blocked filter can cause the machine to drain poorly, leaving cold water sitting around the element and confusing the sensor. Locate the filter behind the small access panel at the bottom front of the machine, place a towel and shallow tray underneath, unscrew the cap slowly, and clear any debris. Refit securely and test again.
- 4
Check the NTC temperature sensor
Unplug the machine and remove the back panel (or front panel on some models — check your model's service diagram). Locate the NTC sensor clipped to the heating element housing. Disconnect its wiring plug and use a multimeter set to resistance (Ω) to test it. At room temperature, a healthy NTC typically reads between 4,000 and 10,000 ohms depending on the model. A reading of zero or infinity suggests the sensor needs replacing.
- 5
Test the heating element
With the machine still unplugged and the back panel removed, disconnect the two spade connectors from the heating element terminals. Set your multimeter to resistance and touch the probes to the two terminals. A working element typically reads between 20 and 50 ohms. An open circuit (OL or infinity) means the element has failed and needs replacing. Also check between each terminal and the machine's metal chassis — any reading here indicates an earth fault.
- 6
Reseat all wiring connectors
While you have the panel off, inspect every connector on the heating element and NTC sensor. Gently pull each plug free, look for signs of corrosion or heat damage, and push them firmly back into place. Vibration over years of use can cause connectors to sit slightly loose, which is enough to cause intermittent faults. Reassemble the panel and run a test cycle.
- 7
Descale the heating element if limescale is visible
If you can see a white or grey crust on the element, run a dedicated washing machine descaler product according to its instructions — typically on a hot empty cycle. For heavy build-up, the element may need to be removed and soaked, or replaced entirely if it has already tripped its thermal cut-out.
Affected models
Select your model to see its full troubleshooting page.
When to call a service technician
If you have tested both the NTC sensor and the heating element with a multimeter and both components read within their normal ranges, the fault is likely inside the main control board (PCB). PCB diagnosis and replacement requires specialist equipment and knowledge of board-level electronics — this is not a safe DIY repair for most homeowners.
You should also contact a service technician if you find any signs of burning, melted plastic, or scorching around the element housing or wiring loom, or if the machine trips your household circuit breaker when it attempts to heat. These symptoms suggest an electrical fault that needs professional assessment before the machine is used again.
Spare parts and service
Visit our partners for spare parts and service
Spare parts
Book a repair
Frequently Asked Questions
Can I still use my Bosch washing machine while it shows E63?
It is not advisable to continue using the machine with an active E63 fault. The machine will not heat the water properly, meaning your laundry will not be cleaned or sanitised effectively. There is also a small risk that a failing element could develop an earth fault, so it is best to diagnose and resolve the issue before running further cycles.
How do I know if it is the heating element or the NTC sensor that has failed?
The most reliable way is to test both components with a multimeter. The NTC sensor should show a resistance reading in the thousands of ohms at room temperature; the heating element should show a low resistance of roughly 20–50 ohms. A reading of zero or infinity on either component points clearly to the faulty part. If both test fine, the wiring or control board is the next area to investigate.
How much does it cost to replace a Bosch washing machine heating element?
A replacement heating element for a Bosch washing machine typically costs between £20 and £50 for the part itself, depending on the model. If you are comfortable doing the replacement yourself, that is the total cost. A service technician call-out and fitting will add labour charges on top, so it is worth weighing this against the age and overall condition of the machine.
Will E63 clear itself after replacing the faulty part?
On most Bosch models, the error code will clear once the fault is resolved and the machine is power cycled — unplugged for two minutes and restarted. If the code persists after a confirmed repair, it is worth checking whether there is a secondary fault or whether the control board has stored the error and needs a manual reset sequence, which is described in your model's user manual.
Is E63 the same fault on all Bosch washing machine models?
E63 consistently relates to the heating circuit across Bosch washing machine ranges, but the exact component that triggers it and the location of parts can vary between models. Always cross-reference with your specific model's documentation or the rating plate inside the door before ordering parts, as element shapes, sensor types, and connector configurations differ across the product range.