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 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 certified Thermador technicians carry genuine OEM parts and serve all 50 states with a 30-day labor warranty.
