Neff E09 on a dishwasher
Flow heater fault — the dishwasher is not heating the water.
The same code appears on Bosch and Siemens machines — they share the same control platform.
Needs an engineer
Mains electrical, gas or sealed-system work
About 2 hr to work through
£120–£280
What E09 actually means
The flow-through heater built into the circulation pump housing has failed, or the board cannot drive it. Dishes come out wet and greasy because there was never any hot water in the cycle. Unlike the blockage codes, this one is not a householder fix: the heater is integral to the pump assembly on most Bosch machines, which makes it both an expensive part and a proper strip-down.
Before you start
Electrical safety: The flow heater is a high-current mains component. Do not attempt to test or replace it without the appliance isolated and the competence to work on mains wiring.
What causes it, most likely first
Failed flow-through heater element
Most likelyThe element goes open circuit with age and limescale. On most Bosch machines it is part of the heat pump assembly rather than a separate part, which is what drives the cost.
Heating element / flow heater£25–£90 for the partEngineerHeavy limescale on the heater
CommonIn a hard-water area, running without dishwasher salt lets scale insulate the element until it overheats and fails. Worth knowing because it is preventable and will happen again if the salt is not kept topped up.
Failed NTC temperature sensor
OccasionalIf the sensor stops reporting a rising temperature the board assumes the heater has failed even when it is working.
Control board heater relay failure
OccasionalThe relay switching power to the heater welds or fails open. Requires live testing to distinguish from a dead element.
Main control board (PCB)£70–£240 for the partEngineer
How to fix it, step by step
Confirm the symptom
Run a hot programme and open the door carefully near the end. If the interior and the dishes are cold and there is no steam, the heater genuinely is not working.
60 minCheck the salt and rinse-aid levels
Top the salt reservoir up and set the water hardness correctly in the machine settings. This will not fix a failed element but it stops the replacement failing the same way.
10 minPower-cycle to rule out a latched fault
Switch off at the wall for five minutes and restore power. A one-off glitch will clear; a genuine heater failure will not.
10 minGet a quote before committing
On most Bosch dishwashers the heater comes as part of the pump assembly, so this is one of the repairs where the bill can approach the price of a replacement machine. Ask for the total including parts and labour, then weigh it against a graded replacement before saying yes.
10 min
Need an engineer for this E09?
We list 75 dishwasher repair businesses across the UK, 28 of which are Neff-authorised. Diagnostic callouts typically start around £55, and many will put that towards the repair if you go ahead.
- 0800 037 4915London
- 01344 669700BracknellSame day
- 01634 557996Chatham
Parts you might need
Typical UK prices for the part alone, before fitting. Worth knowing before you accept a quote — the part is often a small share of what a repair is priced at.
Heating element / flow heater
Heats the wash water. On modern machines it is integrated into the pump housing, which raises the part cost considerably.
£25–£90Main control board (PCB)
The appliance control board. Usually the diagnosis of last resort — genuine boards are expensive and often need model-specific configuration.
£70–£240
Worth repairing, or replace it?
At the top of this range the repair costs a significant share of a graded replacement, which typically starts around £190. Worth getting the quote first, then deciding — on a machine under about five years old a repair usually still wins.