Dishwasher
E8
The E8 error code on a Bosch dishwasher indicates the water level in the appliance is too high — it’s a moderately serious fault that will stop your machine from completing a cycle and must be resolved before running another wash.
What does this error mean?
E8 signals that the dishwasher’s internal sensor has detected an abnormally high water level inside the tub, beyond what the programme expects at that stage. This is typically a flood-protection response — the machine is stopping itself to prevent water from spilling onto your kitchen floor. It does not necessarily mean there is a leak, but it does mean something in the water management system is not working correctly.
Est. repair cost
£100–£180 professional repair (parts + labour); £15–£50 DIY if limited to filter cleaning or drain hose clearance
🔍 Likely causes
🛠️ Step-by-step fix
Switch the dishwasher off at the mains and leave it for 10–15 minutes, then power back on and run a short cycle — a temporary sensor glitch can sometimes cause a false E8 and a hard reset clears it.
Remove the bottom basket and pull out the filter assembly (twist anticlockwise). Rinse the mesh filter and cylindrical filter under the tap to clear any food debris, then refit firmly — a blocked filter is one of the most common causes of drainage-related errors.
Check the drain hose at the back of the machine: ensure it is not kinked, squashed behind the appliance, or blocked where it connects to your sink’s waste pipe or U-bend. Disconnect the hose from the sink end and check for blockages.
Inspect the base tray beneath the dishwasher — if you see water pooled there, the float switch (a small plastic device in the base) may have been triggered by a minor leak. Tilt the machine slightly forward (with a helper) to drain the base tray, then dry it with a cloth and run the machine again.
Listen during the drain cycle: if the drain pump sounds like it is running but water is not clearing, the pump impeller may be blocked. Remove the filter, reach into the sump, and carefully feel for any debris (glass, a food wrapper, a broken arm cap) jamming the pump — remove it if safe to do so.
If none of the above resolves the fault, do not attempt to open the control board housing or replace the inlet valve yourself — call a qualified appliance engineer at this stage.
📞 When to call a professional
If the E8 error returns after you have cleaned the filter, cleared the drain hose, and dried out the base tray, you are likely looking at a failed inlet valve, drain pump, pressure sensor, or control board — all of which require a qualified appliance engineer to diagnose and replace safely. When you call, tell them: ‘My Bosch dishwasher is showing an E8 error — it appears to be detecting an overfill or high water level and will not complete a cycle.’ This gives the engineer enough to arrive with the likely parts.
⚖️ Repair or replace?
A professional repair for an E8 fault — typically a new inlet valve (£40–£70 part) or drain pump (£30–£60 part) plus labour — usually costs £100–£180 in total across the UK. If your Bosch dishwasher is under 7 years old, repair is almost always the right call given Bosch’s build quality and typical 10–15 year lifespan. If the machine is over 10 years old and the control board is at fault (£80–£150 just for the part), replacement with a new mid-range Bosch model at £450–£600 is worth serious consideration.