Normal sounds
Gentle humming (wash pump): The variable-speed wash pump hums during the wash cycle — this is normal operation. Star Sapphire models are rated at 39 dBA, barely louder than a library.
Water rushing/spraying: Water hitting the tub walls and dishes as spray arms rotate. Louder at the start of a cycle when water pressure is highest.
Soft clicking (detergent dispenser): The dispenser door opening mid-cycle makes a click. Normal timing varies by cycle.
Drain pump whirring: A brief 30-60 second whirring at the end of each drain phase. The brushless DC drain pump is quieter than traditional pumps but still audible.
Abnormal sounds — investigate
Grinding: Debris in the wash pump or drain pump impeller. Check the drain filter for trapped glass or food particles.
Hammering/banging: Water hammer from the inlet valve — often caused by high water pressure or a sudden valve closure. An anti-hammer arrestor on the supply line can fix this.
Continuous buzzing: Water inlet valve vibrating — may indicate a partially clogged valve screen or failing solenoid.
Rattling: Loose spray arm, items on the top rack hitting each other, or a loose panel on panel-ready installations.
When to call a technician
Grinding that persists after cleaning the filter, any burning smell, or a completely silent wash pump (should hum) all warrant professional inspection.
Need professional Thermador Dishwasher service?
If troubleshooting doesn’t resolve the issue, our factory-certified Thermador technicians can help. We service all Thermador Dishwasher models across all 50 states with genuine OEM parts and a 30-day labor warranty. Schedule service online — same-day booking available.
Related Thermador resources
- Thermador Dishwasher repair service — certified technicians in all 50 states
- Thermador error code database — search all Dishwasher error codes
- Thermador model database — specifications and repair info by model number
- Thermador official site — official specifications, manuals, and product information
Important notes for Thermador dishwasher owners
- Always use genuine OEM parts — aftermarket components may fit but can compromise performance, safety, and warranty coverage on Thermador appliances
- Never ignore error codes — Thermador codes are diagnostic aids designed to prevent small issues from becoming major failures. Address them promptly
- Keep your owners manual accessible — it contains model-specific maintenance schedules and troubleshooting trees. Digital versions are available on the Thermador official site
- Document issues before calling — note error codes, symptoms, when they started, and patterns. This helps the technician diagnose faster
- Use surge protectors — power fluctuations damage electronic control boards. A quality surge protector protects your investment
When DIY troubleshooting is not enough
Some Thermador dishwasher issues can be resolved with the steps in this guide. However, call a certified technician immediately if you encounter:
- Gas smell (gas models) — turn off the appliance, open windows, leave the house, call from outside
- Burning smell or smoke — disconnect power immediately. Do not use until inspected
- Electrical sparking — turn off at the circuit breaker. Wiring or component failure
- Water leaking inside walls — shut off supply and call to prevent water damage
- Error codes that return after power reset — persistent codes indicate real component failure
- Sealed system issues — compressor, refrigerant work requires EPA-certified technicians
Schedule service online — our factory-certified Thermador technicians carry genuine OEM parts and serve all 50 states with a 30-day labor warranty.
