Dishwasher
E05
The E05 error code on a Bosch dishwasher points to a problem with the water temperature sensor (NTC sensor) or the heating circuit — the system that heats the water during a wash cycle. It’s one of the more common Bosch fault codes and, while it can sometimes be resolved at home, it does occasionally require a professional repair. In this guide, you’ll learn exactly what triggers E05, the most likely causes, safe DIY steps to try first, and honest advice on when it’s time to call an engineer.
What does this error mean?
The E05 code means your Bosch dishwasher has detected a fault with the water temperature monitoring system. Specifically, the appliance’s control board has received an abnormal reading — or no reading at all — from the NTC (Negative Temperature Coefficient) thermistor, which is a small sensor that continuously measures the water temperature inside the wash tub. When the control board can’t verify that the water is reaching the correct temperature (typically between 45°C and 75°C depending on the programme), it stops the cycle and displays E05 as a safety measure. In some cases, the fault lies with the NTC sensor itself being faulty or disconnected; in others, the heating element that actually warms the water has failed and the temperature never rises as expected. Either way, the dishwasher is telling you: ‘I can’t confirm the water is hot enough to wash safely and effectively.’
Est. repair cost
DIY NTC sensor replacement: £8–£20 for the part. Professional repair (call-out + labour + parts): £80–£180 typically, rising to £150–£300 if the heating element or PCB needs replacement.
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 — Perform a hard reset: Switch the dishwasher off at the wall socket and leave it unpowered for at least 5 minutes. This fully discharges the control board’s capacitors. Switch it back on, select a 60°C cycle, and run it. A one-off software glitch can occasionally produce a false E05, and a hard reset clears it. No tools required.
Step 2 — Check and refill the dishwasher salt: Open the salt reservoir (usually located in the base of the wash tub, beneath the lower basket). If it’s empty or nearly empty, refill it with dishwasher-specific salt (not table salt). In hard-water areas, low salt allows limescale to build up rapidly on both the heating element and the NTC sensor. Run a full 60°C cycle afterwards.
Step 3 — Run a descaling cycle: Purchase a dishwasher descaler such as Finish Dishwasher Cleaner or Durgol (available from most UK supermarkets for £3–£8). Run the descaler in an empty machine on the hottest available cycle. Significant limescale on the heating element or sensor can cause temperature misreadings, and descaling may resolve the issue entirely. Do this once, then retest.
Step 4 — Inspect and clean the filters and sump area: Pull out the lower basket and remove the cylindrical filter and flat mesh filter from the base of the tub. Rinse them thoroughly under the tap and use an old toothbrush to remove any debris. A heavily blocked filter can restrict water circulation around the heating element and sensor. Refit securely and run a test cycle. No tools required.
Step 5 — Check the door seal and confirm the door is latching fully: A door that isn’t closing and sealing properly can allow heat to escape, preventing the water from reaching the target temperature. Inspect the rubber door gasket for cracks, tears, or debris. Clean it with a damp cloth. Ensure the door clicks firmly shut and the latch engages. Replacement door seals for common Bosch models are available online for £10–£25 and are a straightforward DIY fit.
Step 6 — Locate and visually inspect the NTC sensor connections (ONLY if comfortable doing so): Switch off and unplug the dishwasher from the mains before proceeding. Carefully remove the lower kick-plate panel at the front base of the machine (usually held by two screws or clips). The NTC sensor is a small cylindrical component mounted on or near the sump/heating element assembly, with a two-wire connector. Without touching any other electrical components, check that the two-pin connector is fully pushed home and that the wires are not visibly damaged, burned, or corroded. If a connector is loose, carefully reseat it. Replace the panel, plug in, and test. If you are not confident working near the base of the appliance, skip this step and call a professional.
Step 7 — Test the NTC sensor resistance with a multimeter (DIY-competent users only): With the dishwasher unplugged, disconnect the NTC sensor connector. Set a digital multimeter to resistance (Ω) mode. At room temperature (approximately 20°C), a healthy Bosch NTC sensor should read approximately 4,000–6,000 ohms (4–6 kΩ). A reading of zero (short circuit) or infinity (open circuit/no reading) confirms the sensor has failed and needs replacing. A replacement Bosch NTC sensor (part numbers vary by model — check your model number on the inner door frame) typically costs £8–£20 and is straightforward to fit by disconnecting the old one and plugging in the new one. You will need a multimeter and a small Torx or Phillips screwdriver.
Step 8 — Visually inspect the heating element for visible damage: With the dishwasher still unplugged and the lower basket removed, look at the heating element at the base of the tub (it looks like a metal loop or ring around the sump). Check for any obvious burn marks, cracking, or severe limescale coating. A visually damaged heating element will need professional replacement — do not attempt to replace the heating element yourself as it involves draining the sump, disconnecting multiple electrical terminals, and resealing the sump assembly. Call a qualified appliance engineer.
Step 9 — Check your model’s specific service manual: Bosch dishwashers are sold under multiple sub-brands in the UK including Neff and Siemens (which share the same platforms). Your model number (printed on a sticker inside the door frame) can be used to find the exact wiring diagram and component part numbers on sites such as Ransom Spares or 4ourhouse. This ensures you order the exact correct NTC sensor or heating element for your specific machine before attempting any repair.
📞 When to call a professional
Stop DIY and call a qualified appliance engineer if: the E05 error persists after you’ve completed the reset, descaling, and filter-cleaning steps; your multimeter test confirms the NTC sensor is faulty and you’re not confident replacing it yourself; you’ve replaced the NTC sensor but the fault code has returned; or you suspect the heating element or main PCB is the root cause. You should also call a professional if you notice any burning smell, scorch marks, or tripped circuit breakers associated with the fault — these indicate a potential electrical hazard. When you call, tell the engineer: ‘My Bosch dishwasher [give your full model number from the door sticker] is showing an E05 error code. I’ve tried a hard reset and a descaling cycle. I’ve checked the NTC sensor connector and [describe what you found].’ This saves diagnostic time and may reduce your call-out charge. Look for an engineer registered with DASA (Domestic Appliance Service Association) or check reviews on Checkatrade or Trustpilot. Most reputable engineers will offer a fixed-price diagnostic visit.
⚖️ Repair or replace?
**Repair vs Replace — the honest UK homeowner’s guide:**
If your Bosch dishwasher is under 5 years old, repair is almost always the right call. Bosch is one of the most repair-friendly dishwasher brands in the UK — spare parts (including NTC sensors, heating elements, and PCBs) are widely stocked by UK suppliers such as Ransom Spares, 4ourhouse, and eSpares, often with next-day delivery. A professional repair for an E05 fault typically costs £80–£180 all-in (call-out, labour, and parts), which is well worthwhile against the £350–£900 cost of a comparable new Bosch dishwasher.
If your dishwasher is 8–10 years old or more, weigh the repair cost against replacement carefully. As a general rule, if the repair quote exceeds 50% of the cost of an equivalent new machine, replacement makes more financial sense — especially if you’ve had other faults in recent years. Bosch dishwashers typically have a lifespan of 10–14 years with proper maintenance.
If the fault has been diagnosed as a failed main PCB (control board), costs can rise to £150–£300 for parts and labour, at which point replacement of an older machine is usually the wiser investment.
**Our recommendation:** For machines under 7 years old with an NTC sensor or heating element fault, repair. For machines over 10 years old with a PCB fault, seriously consider replacing with a new Bosch Series 2 or Series 4 model.