A dishwasher in an apartment runs a few feet from a neighbor's wall, often under someone else's bedroom and sometimes across the room from your own bed. In a small kitchen the 18 inch built-in is the usual fit, and its noise figures are higher than the full-size models get.
The dishwasher is only one of the machines a neighbor can hear; the rest are on our page about keeping an apartment quiet.
For every 18 inch built-in dishwasher we could find, we read the product pages, spec sheets and manuals, and ranked the models on the figures their makers publish. This guide adds what the main dishwasher guide does not cover in depth: running one at night, silencing the beep, the hookups a rental kitchen already has, and fitting an 18 inch opening.
Our picks are listed above, with full specifications for each.
Ranked dBA against dBA
Most makers print a dBA figure, and we ranked only those against each other:
- 44 dBA: Bosch 800 Series, in three versions: SPE68C75UC, the panel-ready SPV68C73UC and the bar handle SPX68C75UC.
- 46 dBA: Bosch 300 Series SPE53C55UC.
- 47 dBA: GE Profile PDT145SSLSS.
- 48 dBA: Blomberg DWS51502SS, from the product title on Blomberg's site.
- 49.0 dBA: Summit DW18SS4 and DW18SS4ADA.
- 52 dBA: Frigidaire FFBD1831US and Midea MDF18A1AST.
Two figures sit outside that list. Miele lists 44 dB(A) re 1 pW for the G 5482 SCVi SL, which is sound power, the total noise a machine emits, rather than the level you hear at a distance. Our sound power vs sound pressure explainer covers why the two cannot be ranked together. Danby says its DDW18D1ESS is "Designed to operate at 51 decibels" without saying dBA, and a figure without its weighting cannot be ranked against a dBA figure either.
None of the dBA makers names the cycle or the test standard behind its number. So treat a gap of one or two dBA between brands with caution, and trust comparisons within one brand most. Bosch's 44 against its own 46 is the cleanest comparison in this list.
Decibels are logarithmic. Roughly every 10 dBA sounds twice as loud, so the 8 dBA between the Bosch 800 Series and the 52 dBA Frigidaire is close to a doubling, and the 5 dBA between Bosch and Summit is a clear step. Small gaps matter more than they look.
The full-size comparison is sobering. Full-size Samsung, Bosch and JennAir models list 38 dBA, so the quietest 18 inch figure is 6 dBA higher. A smaller cabinet has less room for insulation, and the makers price quiet at the top of the range.
A dBA figure also describes sound in the air, not vibration through a cabinet, a floor or the wall behind the sink. Bosch's manual lists sounds the rating does not cover. "Filling valves making knocking noises" is, it says, "Caused by the domestic installation," and "Can only be remedied in the home installation." That is a plumbing fix, and in a rental it is the landlord's. Bosch also warns that "With a small load the water jets directly strike against the tub," and says to distribute the dishware evenly. GE's manual lists rattling dishes and silverware bumping the door, and says to move tall utensils to the upper rack. Loading is the one noise control a renter has complete control over.
Running it at night
Every pick has a delay start. Bosch's manual says "You can delay the start of the wash cycle by up to 24 hours." Summit and Miele also offer 24 hours. GE's PDT145 stops at 12 hours, and Frigidaire's spec sheet lists 1 to 24.
The run times are the part to plan around. Bosch's Normal cycle takes 2:15 to 2:20 on both the 300 and 800 Series, and Auto 1:50 to 2:15 on the 300 and 2:00 to 2:20 on the 800. GE gives AutoSense a range of 1 hour 30 minutes to 2 hours, and that is washing time only, before drying. So a machine started at 11 pm is still running after 1 am.
That cuts two ways in an apartment. If the neighbor's bedroom shares the wall behind your sink, a night run puts two hours of pumping and spraying into their quietest hours. If your own bed is the problem, as in a studio, a delay that runs it while you are at work may be the quieter answer than any figure. Bosch's app also offers Smart Start, which the manual says "automatically determines the best time for the program to start" from the preferences you set.
Short cycles are the trade-off quiet costs in reverse. Bosch's 800 Series has a 30 minute Express cycle and Summit a 35 minute wash, and Miele says its QuickIntenseWash cleans and dries "in under 60 min." No maker publishes a noise figure for a short cycle, so we cannot say whether they are louder, only that they are over sooner.
Beeps, chimes and lights
Through a shared wall at night, a beep can wake someone the wash did not. This is where the manuals differ most.
GE is the clearest. It lists an "Audible End-of-Cycle Signal," and its manual says "To turn the dishwasher control sounds ON/OFF, press the Wash Temp button 5 times within 5 seconds." GE also says the dishwasher "will beep every minute to remind you to close the door" if you open it mid-cycle, so close it again rather than leave it ajar.
Bosch's 18 inch manuals list rinse aid, intensive drying, Wi-Fi and remote start in their basic settings, and we found no setting for an end signal. The 800 Series lists InfoLight among its special features, and the 300 Series does not. Bosch also says the machine switches off automatically 10 minutes after the cycle ends.
Miele's data sheet lists the "In-operation indicator" as "acoustic." Summit's product page says nothing about the end signal either way.
The hookups a rental kitchen has
An 18 inch built-in needs a hot water line, a drain and power, the same as a full-size machine. If the kitchen already had a dishwasher, those are usually in the sink cabinet. What differs between models is the power.
Every pick runs on an ordinary 120 V supply. Bosch includes a power cord with a 3-prong plug on both the 300 and 800 Series, and says the machine can be hardwired instead with an optional junction box. Summit's DW18SS4 "Includes a pre-installed power cord with NEMA 5-15P 3-pronged plug," the standard household plug. GE's PDT145 is hardwired unless you buy its cord kit, and GE says a cord needs a 3-prong grounding receptacle in the sink cabinet's rear wall, "6" min. or 18" maximum from the opening," and adds: "Do not use an extension cord or adapter plug with this appliance." Danby's FAQ says the same about extension cords.
The drain needs care too. Bosch says part of the drain hose must be raised between 33 and 43 inches above the cabinet floor, and GE says an air gap "must be used when required by local codes and ordinances." In a rental, ask before you touch the plumbing or the wiring. If the answer is no, a countertop or rolling portable connects to the faucet instead, and our countertop and portable guide ranks those.
Fitting an 18 inch opening
"18 inch" is the nominal width. The machines are narrower, and the cutouts are specific:
- Bosch 300 and 800 Series: cutout 17 3/4 inches wide, 32 1/8 inches high and 24 inches deep. The panel-ready SPV68C73UC needs only 22 7/16 inches of depth.
- GE Profile PDT145: cutout 18 by 24 by 32.5 inches, with a height of 32.5 to 34 5/8 inches on its legs. GE says it is "Great for 34" counter top heights and raised subfloors."
- Summit DW18SS4: 17.75 inches wide, with a cabinet height of 34.25 inches and legs that adjust from 33.5 to 35 inches. The DW18SS4ADA is 32.25 inches high for lower counters.
- Miele G 5482 SCVi SL: a niche 17 3/4 inches wide, 32 1/8 to 34 3/4 inches high and 21 3/4 inches deep.
Measure the door swing as well. With the door open, Summit gives a depth of 45.5 inches, Frigidaire 45 1/2 and Miele 45 7/8. In a galley kitchen that can block the path while you load it.
Check the width field on the maker's page, not the retailer's category. GE lists a 24 inch cabinet width for its GDT226 models, which share a manual with the 18 inch PDT145.
What quiet costs at 18 inches
The quietest dBA figure costs the most: $1,399 for the 800 Series, against $1,099 for the 300 Series and $929 on clearance for the GE Profile. Capacity is small whichever you choose, 8 to 10 place settings. Normal cycles run past two hours. And stock was thin: Bosch's store showed its 18 inch models out of stock or with an unclear label, GE's was out of stock online, and Blomberg's showed no price at all. If a model is gone, the 300 Series at 46 dBA is the one we would fall back on.
We did not measure any of these dishwashers. Every figure is the maker's own, quoted as published with the unit and any condition attached, and we compared dBA only with dBA.
