Whirlpool Dishwasher 3-3 — What It Means & How to Fix It
Also shown as F3 E3 on some models.
The machine could not calibrate its soil sensor on the last run — most often because used water is siphoning back into the tub through a failed one-way valve in the drain hose, so the water never looks clean.
What this code means
3-3 (F3 E3 on display models) fires when the optical water indicator cannot establish a clean-water baseline. Whirlpool's guidance points first at the check valve in the drain hose: if that one-way valve fails, drained water flows back into the tub and the sensor never sees clear water to calibrate against. A genuine calibration miss is the other, less common cause.
Do not read this as a plain sensor failure — that is 3-1. The 3-3 variant specifically implicates back-flow, so the drain path holds the useful checks. Light-only models flash three, pause, three.
Most likely causes
| Cause | How likely | DIY-fixable? |
|---|---|---|
| Failed check valve in the drain hose letting used water back-flow | Common | Partly — inspect the hose |
| Drain hose not looped high under the counter, allowing siphon-back | Common | Yes — re-route the loop |
| Fouled optical sensor preventing calibration | Occasional | Yes — clean filter and sump |
| Failed thermistor/OWI sensor | Less common | No — technician job |
What you can try yourself
- Cut power for two minutes, then run a short cycle and watch whether dirty water rises back into a tub that should be draining — back-flow is the tell for this code.
- Under the sink, confirm the drain hose rises in a high loop secured near the underside of the countertop before dropping to the disposal or drain tee; a sagging hose siphons used water back in.
- If you have an air gap (the small cylinder on the sink deck), pop its cap and clear any gunk — a blocked air gap encourages back-flow.
- Clean the filter and wipe the sump so the optical sensor has a clear window to calibrate through.
- If dirty water still returns after the loop and air gap are right, the one-way check valve built into the drain hose has failed — replacing that hose section is the fix, and a technician can confirm it quickly.
When to call a technician
- Dirty water keeps appearing in a freshly drained tub after the loop, air gap, and filter all check out.
- 3-3 persists with a clean sump and a correctly routed hose.
- Dishes come out gritty or re-filmed — the sign the machine is washing in its own drain water.
Typical professional repair cost: Drain hose with integrated check valve replacement typically runs $100–$220 including labor.
Frequently asked questions
What is the drain check valve and why does it matter here?
It is a one-way flap built into the drain hose near the pump that stops water you just pumped out from flowing back. When it wears or sticks open, used water siphons into the tub — which both dirties your dishes and stops the soil sensor from finding a clean baseline, triggering 3-3.
Why does the drain hose need a high loop?
The loop — or an air gap on the sink deck — breaks any siphon between the dishwasher and the household drain. Without it, gravity can pull sink or drain water back toward the tub. It is the cheapest fix on this list and a common miss after a new install or a disposal swap.
Could this just be a dirty sensor?
Occasionally. If the drain path is clearly fine and no water backs up, a fouled optical window can stop calibration on its own. Clean the filter and sump and run a cleaning cycle before assuming the check valve — but back-flow is the more common cause of this particular code.
Related Whirlpool codes
- Whirlpool Dishwasher 6-1 The control board never saw water arrive after opening the fill valve — usually a supply problem under the sink rather than a failed part inside the unit.
- Whirlpool Dishwasher 8-1 The tub drained too slowly or not at all — food debris in the filter, buildup in the drain hose, or the garbage-disposal knockout plug are the usual culprits.
- Whirlpool Dishwasher 7-1 The heating circuit isn't doing its job, so water stays cold and dishes finish wet — and because everything involved is on mains power, the repair belongs to a technician.
- Whirlpool Dishwasher 9-1 The control lost track of the diverter — the rotating disc that aims water at different spray arms — usually debris interfering, a leaking diverter seal, or the diverter motor itself.
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