What Does Error Code E30 Mean on a Bosch Washing Machine?

Bosch Updated 8 April 2026
Quick Fix

Check that the wiring connector on the NTC sensor at the back of the drum heater is firmly seated — unplug the machine, reseat the connector, then restart the cycle to see if the error clears (takes about 10 minutes).

Fault description

Error code E30 points to a problem with the NTC (Negative Temperature Coefficient) sensor inside your Bosch washing machine. This small component sits close to the heating element and continuously reports the water temperature to the control board throughout the wash programme.

When the control board receives a reading that falls outside the expected range — or receives no signal at all — it triggers E30 and halts the cycle to prevent overheating or ineffective washing. You may notice the machine stopping mid-cycle, failing to heat the water, or refusing to start a programme altogether.

In many cases the sensor itself is not broken; a loose wire connection or a build-up of limescale around the heater assembly is enough to cause a false reading. Working through the checks below in order will help you identify whether this is a simple fix or a component replacement job.

Causes

  • Loose or corroded NTC sensor connector — The wiring connector that links the NTC sensor to the main harness can work loose over time due to vibration. Corrosion on the terminals can also interrupt the signal, producing an intermittent or absent temperature reading.
  • Defective NTC temperature sensor — The sensor itself can fail, either developing an open circuit or drifting out of its correct resistance range. When this happens the control board cannot get a reliable temperature reading and locks out the programme.
  • Faulty or failed heating element — The NTC sensor is mounted directly on or very close to the heating element. If the element has burned out or shorted, it can affect the sensor's readings and trigger E30 alongside heating problems.
  • Heavy limescale build-up on the heater assembly — In hard-water areas, limescale can coat the heating element and the sensor, insulating them from the water. This causes the sensor to report inaccurate temperatures and can eventually damage both components.
  • Wiring harness damage — The wires running between the NTC sensor and the control board can become pinched, chafed, or broken, particularly if the machine has been moved recently. A break anywhere in the circuit will prevent the sensor signal from reaching the board.
  • Main control board fault — Less commonly, the control board itself may be unable to process the sensor signal correctly due to a component failure on the board. This is usually only suspected after all other causes have been ruled out.

Step-by-Step Fix

  1. 1

    Power cycle the machine

    Switch the machine off at the programme dial, unplug it from the mains, and leave it for two minutes. Plug it back in and run a short cycle. Occasionally a temporary signal glitch triggers E30 and a full power reset is enough to clear it.

  2. 2

    Run a hot maintenance wash

    Select a 90°C cotton cycle with no laundry and add a washing machine cleaner or a cup of white vinegar. This can dissolve light limescale deposits around the heater and sensor, restoring accurate temperature readings without any dismantling.

  3. 3

    Inspect and reseat the NTC sensor connector

    Unplug the machine and remove the back panel (usually held by two or three screws). Locate the NTC sensor on the heater assembly at the base of the drum. Disconnect the wiring connector, check the terminals for corrosion or discolouration, and press it firmly back into place. Corroded terminals can be gently cleaned with fine sandpaper or electrical contact cleaner.

  4. 4

    Test the NTC sensor resistance

    With the machine unplugged, disconnect the sensor and use a multimeter set to resistance (Ohms). At room temperature (around 20°C) a healthy NTC sensor typically reads between 4,000 and 6,000 Ohms — check your model's service data for the exact value. A reading of zero, infinity, or wildly outside the expected range confirms the sensor has failed and needs replacing.

  5. 5

    Check the heating element

    While the back panel is off, test the heating element terminals with a multimeter set to continuity. A healthy element will show continuity; an open circuit reading means the element has failed. Also check for any visible burn marks or corrosion on the element body, which would confirm it needs replacing.

  6. 6

    Inspect the wiring harness between sensor and control board

    Trace the wires from the NTC sensor back towards the control board, looking for any pinched, melted, or broken sections. Gently flex the harness along its length — a break that only shows under movement can cause an intermittent fault. Damaged sections of wire should be repaired or the harness replaced.

  7. 7

    Replace the NTC sensor

    If the sensor has tested faulty, fit a compatible replacement part for your specific Bosch model. The sensor usually unclips or unscrews from the heater assembly and the connector pulls off. Fit the new sensor, reconnect the wiring, reassemble the panel, and run a test cycle to confirm the error has cleared.

Affected models

When to call a service technician

If you have replaced the NTC sensor and checked all wiring connections but E30 continues to appear, the fault may lie with the main control board or a deeper wiring issue that is difficult to diagnose without specialist equipment. Similarly, if you find the heating element has failed and you are not comfortable working around mains-voltage components, a service technician should carry out the replacement safely.

You should also contact a service technician if the machine shows signs of burning smells, scorch marks near the heater assembly, or if the drum is getting excessively hot — these symptoms suggest a more serious electrical fault that should not be left unattended.

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Frequently Asked Questions

Can I still use my Bosch washing machine while it shows E30?

It is not advisable. The machine has stopped the cycle because it cannot confirm the water temperature is safe and correct. Running it in this state risks either overheating the water or washing at the wrong temperature, and could cause further damage to the heating components.

How do I know if it is the NTC sensor or the heating element that has failed?

Test each component separately with a multimeter. The NTC sensor should show a resistance reading within the specified range for your model at room temperature. The heating element should show continuity. Whichever component gives an out-of-range or open-circuit reading is the faulty part.

Is E30 the same as E3 on a Bosch washing machine?

Not necessarily — Bosch uses different error code formats across different model ranges and production years. E3 and E30 can refer to different faults depending on the machine. Always cross-reference the error code with your specific model's manual or the manufacturer's documentation to confirm the meaning.

How much does it cost to replace a Bosch NTC sensor?

The NTC sensor itself is generally an inexpensive part, typically costing between £10 and £25 depending on the model. If you are comfortable doing the replacement yourself following the steps above, it is one of the more affordable washing machine repairs. A service technician call-out will add labour costs on top of the part price.

Will descaling the machine fix E30 if I live in a hard-water area?

It can, particularly if the fault is intermittent and the machine is otherwise heating water. Heavy limescale insulates the sensor from the water and distorts its readings. Running a dedicated descaling cycle may restore normal sensor behaviour, but if the sensor has already been permanently damaged by scale build-up, replacement will still be needed.