Bosch Dishwasher E18 — What It Means & How to Fix It
Bosch's E18 means the dishwasher is not getting enough water — the level stayed too low — so check the inlet hose, the supply valve, and that water actually reaches the machine before calling for service.
What this code means
E18 is a low-water or filling fault: the dishwasher expected the tub to reach a set water level and it did not, or water is not being moved through as it should. The usual reasons are upstream of the machine — a closed or half-open supply valve, a kinked or clogged inlet hose, or weak flow — which is why several of the checks are genuinely DIY. Bosch specifies the inlet should deliver around 10 litres per minute.
E18 is a filling/low-water code on Bosch dishwashers. It overlaps with the E16/E17 “no water entering” family, so if the display has shown those too, the supply checks below cover all of them.
Most likely causes
| Cause | How likely | DIY-fixable? |
|---|---|---|
| Supply valve under the sink is closed or only part-open | Common | Yes — no tools |
| Inlet hose kinked behind or under the machine | Common | Yes — no tools |
| Clogged inlet screen or low household water pressure | Common | Partly — inspect/clean |
| Inlet valve or flow meter failing | Occasional | No — technician job |
What you can try yourself
- Turn the dishwasher off and confirm the water supply valve under the sink is fully open.
- Ease the machine out and check the inlet hose along its run for kinks or crush points, straightening any you find.
- Close the supply valve, unscrew the hose at the inlet, and check the small mesh screen there for grit; rinse it clean and refit.
- Test your home's pressure by running the kitchen tap — a weak trickle elsewhere points at a household supply problem rather than the dishwasher.
- Restore everything and run a short cycle; if E18 persists with good supply and a clear hose, the inlet valve or flow meter likely needs a technician.
When to call a technician
- E18 stays even though the supply is on, the hose is clear, and pressure is good elsewhere.
- You can hear the fill valve buzzing but little or no water enters.
- Water enters extremely slowly despite strong flow at the tap.
Typical professional repair cost: Supply-side fixes are free to a few dollars. An inlet valve or flow meter replacement by a technician typically runs $130–$280 with labor.
Frequently asked questions
Why is my Bosch dishwasher showing E18 with the water on?
Even with the valve open, a kinked hose, a clogged inlet screen, or weak household pressure can keep the fill below what the machine needs. Work through the hose and screen first; if those are clear, the inlet valve or flow meter may be failing.
Is E18 the same as E16 and E17?
They are in the same water-filling family. E16/E17 lean toward water not entering at all, while E18 is specifically a low level or under-pumping. The DIY supply checks — valve, hose, inlet screen — apply to all of them.
How much water flow does a Bosch dishwasher need?
Bosch specifies roughly 10 litres per minute at the inlet. If your supply cannot deliver that — say, because of a partly closed valve or a clogged screen — the machine can throw E18 even though some water gets through.
Related Bosch codes
- Bosch Dishwasher E15 Water reached the base pan under the tub and Bosch's leak protection locked the machine — sometimes a genuine leak, often a one-off spill or condensation that clears once the base dries.
- Bosch Dishwasher E24 The dishwasher can't drain properly — start with the filter, then the drain hose path, and don't skip checking that the drain pump cover is seated.
- Bosch Dishwasher E25 The drain pump itself is blocked or its cover is loose — and Bosch makes the pump cover owner-accessible, so this is one of the most fixable codes the brand throws.
- Bosch Dishwasher E09 The heating system isn't raising the water temperature — beyond one reset, the flow-through heater is a mains-voltage part that belongs to a technician.
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