What to check first
Use should be limited to documented owner-level checks or retry steps, not normal operation as a workaround.
Basic checks
- From a dry position, confirm that the dishwasher water-supply valve is turned on. Do not force a stiff, leaking or corroded valve.
- Inspect only the visible inlet hose for a kink or damage without pulling out the dishwasher. Do not disconnect plumbing, loosen a hose or open an AquaStop housing.
- Thermador specifies a supply flow rate of 10 l/min. Leave any measurement requiring plumbing disconnection to a qualified plumber; do not perform a bucket flow-rate test as an owner check.
- Stop and use qualified help for leakage, damaged hose, unusual heat, burning smell or electrical warnings.
Applicability
Regional guidance · Thermador dishwashers covered by the United States support library · United States · Official US dishwasher error-code support library
This meaning comes from the Thermador United States dishwasher support library; confirm the exact E-Nr owner manual because available codes, controls, and owner-safe actions can differ by model and market.
Reset or retry steps
- The E18 entry supplies hose/supply checks and a flow-rate value but no power reset or trial-fill programme. Do not add a monitored fill attempt or keep cycling an unresolved warning.
When to call a technician
- Contact Thermador support if E18 remains after the permitted visible supply checks or if the owner path cannot be followed safely.
- Use a qualified plumber for a defective household valve or inadequate 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.
Can I keep using it?
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.
Stop normal use when water is visible or a leak warning is active. Stay clear if water could reach wiring or controls.
- Safe next step
- Follow the code-specific shutdown or protective-drain instructions, turn off water when appropriate, and avoid repeated resets. Do not interrupt a documented protective-drain sequence just to clear the display.
- 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 water supply may not be turned on.
- The visible inlet hose may be kinked or damaged; low water or abnormal pumping does not by itself establish a failed valve, pump, sensor or control.
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 permitted visible supply checks or if the owner path cannot be followed safely. A qualified technician may check the listed symptoms and source guidance against the model's service information before treating any part as failed.