KitchenAid Dishwasher E1 Error — Water Supply Fix

What it means

KitchenAid dishwasher E1 means the control didn't see the expected water fill.
KitchenAid's own support page points at four things in this order: the drain hose is positioned wrong and is siphoning water back out, the under-sink water supply valve is off, the overfill protection float in the front right corner is stuck, or a quick power reset is needed.
None of these need parts.

Affected Models

KitchenAid KDPM, KDTM, KDTE, KDFE built-in dishwashers
KitchenAid KDPE, KDPE804K, KDPE234G series
KitchenAid PrintShield, Architect II, and panel-ready models
KitchenAid KUDS legacy series (older models)
Same codes appear on Whirlpool, Maytag, and JennAir dishwashers (shared platform)

Common Causes

Drain hose installed below the air gap height (siphons water out as fast as it enters)
Water supply shutoff valve under the sink closed
Overfill protection float in the front right corner of the tub stuck or obstructed
Drain hose missing the required high loop above the drain trap
Intermittent control fault that clears with a power reset
House water pressure too low to fill in the allowed time

How to Fix It

Open the water supply valve fully.

Look under the sink for the small shutoff valve on the line feeding the dishwasher.
Turn the handle counter-clockwise until it stops.
A half-open valve causes slow fill and E1.
Check the drain hose loop.

KitchenAid requires the drain hose to connect to the disposer inlet or waste tee above the drain trap, and at minimum 20 inches (50.8 cm) above the floor.
If the hose drops straight down with no high loop, water siphons out while the dishwasher is trying to fill — and the control sees E1.
Strap the hose up to the underside of the counter to form a high loop.
Free the overfill float.

Open the dishwasher and look in the front right corner of the tub.
The small plastic dome is the overfill protection float.
Push it up and down by hand — it should move freely with no resistance.
Pop loose any food debris or labels wedged underneath it.
Power cycle the control.

If steps 1-3 check out, disconnect power for 30 seconds.
For plug-in models, unplug at the under-sink outlet.
For hardwired models, switch the breaker off and back on after 30 seconds.
KitchenAid lists this as the final E1 step.

When to Call a Professional

Every step KitchenAid lists for E1 is owner-doable in 15 minutes.
Only schedule service if the float moves freely, the valve is fully open, the drain hose is correctly looped, and the code returns immediately after a power reset.

Frequently Asked Questions

Why does E1 appear when I can clearly hear water filling?

Because the dishwasher fills AND drains at the same time — the drain hose has no high loop, so water siphons out as fast as it enters.
The control sees the water level never rise to the target and shows E1.
You can hear fill happening, but the tub stays nearly empty.
Strapping the drain hose into a high loop above the disposer fixes this for good.