Thermador puts a noise figure on every dishwasher it sells in the US. On October 5, 2026, its US dishwasher page listed nine models: three series, Star Sapphire, Sapphire and Emerald, each in three versions. Two versions have a stainless door, one with the Professional handle and one with the Masterpiece handle, and the third is custom panel ready. Every product page carries a "Silence Level" row, and the spec sheets repeat it under "dBA".
The figures are simple: 42 dBA for every Star Sapphire, 44 dBA for every Sapphire and 48 dBA for every Emerald. This page lists all nine, quietest first, with the stainless and panel ready models kept apart, because Thermador sells them as separate types. To see how Thermador's figures compare with other brands, see our quietest dishwashers guide; we do not rank other brands here.
Our picks are listed above, with full specifications for each.
How Thermador rates noise
Each product page lists "Silence Level" with a value and the unit dBA, for example "Silence Level 42 dBA". The spec sheets list the same number on a row labeled "dBA". Thermador names no test standard, no distance and, for Sapphire and Emerald, no cycle.
Star Sapphire is the exception, and only partly. Its feature text says "Powerfully Quiet® enjoy a signature cleaning cycle at 42 dBA, perfect for after-dinner conversation." Thermador does not say which program is the signature cycle. The use and care guide lists six programs, Auto, Normal, Quick, Hand Wash, Pots & Pans and Favorite, and none is called Signature.
There is one more wrinkle. Thermador's dishwasher overview page prints the Star Sapphire claim as "a signature cleaning cycle at 42* dBA". The only asterisked note on that page reads "*Available on Star Sapphire® and Sapphire® Models", and it sits under a list of features near the top of the page, not beside the figure. We could not tie the asterisk to any condition on the noise figure, and the product pages print 42 dBA without one.
The use and care guides add a caveat of their own: "The noise level may also vary depending on the items placed in your dishwasher." Our guide to comparing decibel ratings explains why a number with no stated condition is hard to compare across brands, even when it is easy to compare within one.
Every stainless Thermador, quietest first
These are 24 inch built-under dishwashers with a stainless steel door. Every one holds 16 place settings and has a third rack. Prices are Thermador's "Recommended retail price" on October 5, 2026.
- 42 dBA: Star Sapphire DWHD661EFP, Professional handle, $2,499. Star Sapphire DWHD661EFM, Masterpiece handle, $2,499.
- 44 dBA: Sapphire DWHD660EFP, Professional handle, $1,999. Sapphire DWHD660EFM, Masterpiece handle, $1,999.
- 48 dBA: Emerald DWHD640EFP, Professional handle, $1,399. Emerald DWHD640EFM, Masterpiece handle, $1,399.
Every panel ready Thermador, quietest first
These are the custom panel ready versions, listed as "Panel Ready: Yes, Panel and Handle Sold Separately" and "Installation Type: Full-integrated". They are slightly shallower than the stainless models, 23 1/16 inches against 23 3/4, before the panel.
- 42 dBA: Star Sapphire DWHD661EPR, $2,499, with Push to Open.
- 44 dBA: Sapphire DWHD660EPR, $1,999, with Push to Open.
- 48 dBA: Emerald DWHD640EPR, $1,399, without Push to Open.
What changes the number
The series, and nothing else Thermador lists. Within each series, the Professional handle, the Masterpiece handle and the panel ready version all list the same figure. Height, width, capacity and energy use are the same across all nine: 33 7/8 inches tall, 16 place settings, 240 kWh a year and 3.2 gallons a cycle by the spec sheets. So the 6 dBA spread follows the series alone.
What the series add. Thermador does not say why Star Sapphire is quieter than Sapphire, or Sapphire quieter than Emerald. What the spec tables show is that each step up adds hardware. Sapphire and Star Sapphire add StarDry with Zeolite, the Zone Control spray arm and an adjustable third rack over Emerald. Star Sapphire then adds the Crystal Protect water softener, a folding rack for 18 wine glasses and a floor countdown. None of that is offered by Thermador as the reason for the lower figure, so treat it as context, not cause.
The cycle. Thermador's use and care guides list the Normal program at 2:10 to 2:15 hours on Star Sapphire and Sapphire, and 2:15 to 2:35 on Emerald. None of the three guides lists a quiet or night program, so the figure you buy is the figure you get; there is no setting that trades time for silence.
Thermador's quiet features, by name
Powerfully Quiet, Exceptionally Quiet, Effectively Quiet. These are Thermador's names for the three figures. Star Sapphire is "Powerfully Quiet® at 42 dBA". Sapphire's page says "Exceptionally Quiet cleanup has never been so effortless at 44 dBA." Emerald's page says "Effectively Quiet® at 48 dBA for a peaceful kitchen experience", while its spec sheet and the overview page call it "Impressively Quiet" and the overview page adds "At a peaceful 48 dBA, this quiet Dishwasher allows you to enjoy both a powerful clean and the after-dinner conversation." They are marketing names, not settings.
Time Remaining PowerBeam (Star Sapphire). It "shines a countdown of the remaining time of the cycle on the floor." The use and care guide calls the setting TimeLight and says the display is not visible "if the base panel is pulled forward or if the appliance is installed at eye level with the cabinet front fitted flush."
Blue PowerBeam (Sapphire and Emerald). It "projects a blue light onto the floor to indicate when the dishwasher is in use." The guide calls this InfoLight: "The program has ended when the spot of light is no longer visible on the floor." On a quiet machine, a floor light is often the only way to tell it is still running.
Signal and button volume. All three guides list a "Signal volume" setting, where level SL:00 "switches the signal tone off", and a "Button volume" setting, where level bL:00 "switches the button tones off." The guides mark level 2 as the factory setting for both.
Push to Open (panel ready Star Sapphire and Sapphire). The spec sheets say it "uses Auto Door Opening technology to open the door with a push, adding a luxurious touch and the option for a sleek, handle-less design", and mark it "Available on Custom Panel Ready sku only". It is a design feature, not a noise one; Thermador gives no figure for it.
What 42 to 48 dBA means in a kitchen
The decibel scale is logarithmic. Roughly every 10 dBA sounds twice as loud, so the 6 dBA between a Star Sapphire and an Emerald is a clear step, while the 2 dBA between Star Sapphire and Sapphire is hard to hear on its own. Our decibel chart puts these numbers next to everyday sounds. For a dishwasher that shares a room with the dining table, our guide to dishwashers for an open kitchen looks at floor lights, chimes and panel ready models across brands.
Thermador's website and spec sheets carry a BSH Home Appliances Corporation copyright, the same company named on Bosch's US spec sheets. Thermador does not say on these pages how its dishwashers relate to any Bosch model, and we do not assume it. If you are weighing the two, our Bosch dishwasher decibels page lists every Bosch figure the same way this page lists Thermador's.
Price and buying on the day we checked
Every Thermador dishwasher page showed a "Recommended retail price" and a "Where to Buy" link rather than a cart, and the page data marked all nine "Not Buyable" online. Within each series, the three versions share one price: $2,499 for Star Sapphire, $1,999 for Sapphire and $1,399 for Emerald. The panel ready versions cost the same as the stainless ones, but the panel and handle are extra. Dealers set their own prices, so check the exact model number on the day you buy.
We did not measure any of these dishwashers. Every figure is Thermador's own, quoted as published on its US product pages and spec sheets on October 5, 2026, and Thermador names no test standard; only Star Sapphire's feature text mentions a cycle, and it does not say which one.
