What to check first
Can I keep using it?
Use should be limited to documented owner-level checks or retry steps, not normal operation as a workaround.
Do not keep using the appliance if the code points to voltage, wiring, control power, burning smell, smoke, or a possible miswired supply.
- Safe next step
- Use only safe owner-level power checks, then involve a qualified technician or electrician when the source points to wiring or supply voltage.
- Stop when
- Breakers trip, lights dim, the appliance smells hot, wiring may be miswired, or the warning returns after a safe reset.
Do not keep running the appliance when water is visible, a leak warning is active, or water could reach wiring or controls.
- Safe next step
- Stop the cycle if safe, turn off water when appropriate, protect the floor, and avoid repeated resets until the leak source is understood.
- Stop when
- Water is near wiring, cabinetry is getting wet, the leak returns, or the source is not safely visible.
Safety boundaries
Safe first
- Match the exact brand, appliance type, and displayed code first.
- Use the model manual as the final authority for access steps.
- Disconnect power before any service-access step.
Do not do this
- Do not use other cycles as a workaround unless the manual allows it.
- Do not disconnect inlet hoses until the water supply is off.
- Do not bypass locks, float switches, leak sensors, or other safety systems.
Common causes include
- The household water supply is closed, weak, or interrupted
- The visible inlet hose is kinked, crushed, or damaged
- A dishwasher inlet, water-level, pump, sensing, or control condition requires qualified diagnosis
Basic checks
- From a dry position, confirm that the dishwasher water-supply valve is fully open; do not force a stiff, leaking, or corroded valve.
- Inspect only the visible inlet hose for a kink, crushing, or damage without pulling out the dishwasher, disconnecting the hose, or opening an AquaStop or inlet housing.
- Check whether nearby cold-water fixtures have normal flow; do not disconnect plumbing or perform a bucket flow-rate test as an owner check.
- Look for visible water around the dishwasher and stop immediately if a leak, electrical smell, unusual heat, or repeated breaker trip is present.
Reset or retry steps
- One monitored fill attempt is reasonable only after a closed tap is opened or an accessible visible hose is straightened, household flow is normal, and the appliance and floor are fully dry.
- Stop further attempts if E18 returns, filling or pumping remains abnormal, the hose is damaged, or any leak appears; repeated cycles are not a diagnosis.
When to call a technician
- Contact Thermador support if E18 remains after the visible supply checks and one monitored fill attempt, or if no safe external cause is present.
- Use a plumber for a failed household valve or weak supply and qualified appliance service for concealed inlet, pump, water-level, wiring, or control work.
Before approving a paid visit, check warranty status and reviewquestions to ask before repair.
FAQ
What does Thermador Dishwasher code E18 usually mean?
Thermador US documents E18 as a low dishwasher water level or water not being pumped as expected. Model context matters: The Thermador US page combines a low-water-level branch and water-not-pumped-correctly branch under E18; it does not establish one failed component.
Can I keep using the dishwasher with code E18?
Limit use to the owner-level checks described here and in the model manual. Stop using the appliance if the code returns, the appliance behaves abnormally, or a safety warning applies. Do not disconnect a hose, measure flow through loose plumbing, reach into a pump, remove a panel, or perform live electrical tests.
When should I call a technician for Thermador E18?
Contact Thermador support if E18 remains after the visible supply checks and one monitored fill attempt, or if no safe external cause is present. A qualified technician may check Water-inlet system and Water-level and pump-control system against the model's service information before treating any part as failed.