Thermador Range hoods and fans remove grease and moisture from cooking, so they collect dirt and need regular cleaning. Wash exposed metal often with warm suds solution and rinse. If very greasy, use ammonia and water and rinse. Never use abrasive pads or scouring powders as they can scratch the finish. Wash the light bulb when cool with suds then rinse and dry to keep the light clear and bright.
Occasionally clean fan blades of dirt and grease, which can restrict air flow, and cause motor over-heating and fire hazard. Wash the hood with warm, soapy water often. Wash the inside and outside. Rinse the hood and wipe it dry.
If the hood is vented, check the exhaust vent regularly, especially if you find a lessening of the hoods efficiency. Grease clogs or dirt buildup, both of which occur normally with age, can block the vent. The vent should offer an unrestricted air flow.
Occasionally take the metal filter out of the hood. Put the filter in warm, soapy water. Let it soak for a few minutes. Wash and rinse it. Dry the filter and put it back in the hood.
Some hoods have activated charcoal filters. These cannot be cleaned. They should be replaced about once a year. You can buy charcoal filters from stores that sell that brand of hood. Check manual directions for cleaning your hood and fan. If instead you have electronic air cleaners in place of a ducted system, follow manual instructions for regular cleaning of filters.