Miele S4212 Neptune Review

Miele S4212 Neptune

It is no secret that we love Mieles. When testing the Miele S4212 Neptune we were again impressed by the quality of this machine and its ability to clean so thoroughly.

Because the canister of this machine is lightweight, it was easy to transport around our home and between floors for cleaning.

Below you'll find our video review of the S4212 Neptune, and you can read on below that for our full in-depth vacuum review.


  • Purifies air as it cleans
  • Light and easy to maneuver
  • Can be used on all types of flooring


  • Expensive to purchase

Video Review


  • Lightweight and easy to maneuver
  • Automatic cord rewind
  • Good Housekeeping seal of approval
  • Adjustable suction strength

Attachments/On-Board Tools

  • Crevice tool
  • Extension wand
  • Dusting brush
  • Upholstery tool
  • Parquet Brush
  • Turbobrush

Our In-Depth Review

Performance/Using the Miele S4212 Neptune Vacuum

The Miele S4212 Neptune is one of the top canister vacuum cleaners we’ve tested. It’s a typical Miele canister vacuum that excels in air filtration, maneuverability and durability.

While Miele canisters don’t look as cool some Dyson or Hoover vacuums do, they do they job they were designed for; namely cleaning all types of flooring extremely well and at the same time making sure that their air coming out of the exhaust is totally clean.

Performance on Carpets

Miele S4212 Neptune on CarpetsIn an effort to test the Miele Neptune’s ability to clean carpets, we began by attaching the Turbobrush and setting the suction strength to its highest setting.

We used flour to test the vacuum’s ability to capture fine particles. The vacuum did a superb job of getting every visible speck of flour from the carpet.

Next we scattered rice on the floor to test how the vacuum handled medium particles. Again, the vacuum did a great job of getting all the rice off the floor. It didn’t spit any of the rice away as it passed over it.

To test large particles, we spread black-eyed peas on the carpet. The Turbobrush does not have an adjustable height feature and we found this to be problematic for large particles.

Even though the suction was strong, there wasn’t enough clearance for all of the peas to fit beneath the brush and be sucked into the vacuum.

This can be solved by lifting the brush slightly from the floor and thus allowing enough clearance. However, we felt that the non-adjustable height was a disadvantage towards a smooth vacuuming experience.

The Turbobrush is narrow, which is great for cleaning between furniture and small areas, but would be a pain if you had a wide, open area to clean. Also, the Turbobrush is not completely seamless in the way that it moves across carpet and requires a slight bit of effort.

Performance on Rugs

It can be difficult to find a vacuum that can clean light rugs without sucking them off the floor in the process. We were pleased to find that the Neptune’s lower settings allowed us to clean particles off our kitchen rugs without sucking the rug up in the process. This allowed us to move from cleaning our tile to cleaning the rugs with just a turn of the suction control dial.

We were also able to clean our delicate rug tousles on the lower settings without the vacuum sucking them up or snagging them.

Performance on Hard Floors

Miele S4212 Neptune on Hard FloorsUsing the parquet tool, we tested the vacuums performance on hard surface flooring and were impressed with the ease of use and thoroughness of cleaning.

The parquet tool glided smoothly across the floor sweeping the particles and sucking them into the vacuum. The Miele S4212 canister followed easily behind us as we worked.

To test the vacuum’s ability to clean up fine particles, we put flour on the floor. The Neptune easily cleaned it up without leaving a trace behind. Spreading rice on the floor we again put the Neptune to the test on medium particles.

The rice was no challenge for the vacuums suction strength and it collected all the particles from the floor. To further challenge the vacuum, we used black-eyed peas to test the vacuum on large particles. Again, the Neptune easily and entirely cleaned up all the peas and is one of the best vacuums for hardwood floors we’ve tested so far.

Edge Cleaning

Few vacuums will clean debris from the edge without the assistance of an additional attachment. The Miele S4212 Neptune is one of the exceptions. Even when we put flour directly into the edge of the floor and pushed it in with our foot, the vacuum still effectively retrieved it.


Miele S4212 Neptune FilterThe Miele S4212 vacuum comes with a AirClean and pre-motor filter as well as an AirClean dustbag.

The AirClean filter is made of electrostatically charged multi-ply material. This helps retain dust particles. They claim that this filter retains 99.95% of particles down to .5 of a micron and 94% of particles down to .3 of a micron.

The AirClean dustbag is composed of nine layers of electrostatically charged material. These thick bags not only work to trap dirt and allergens, but are more resistant to rips and tears and help keep debris out of your home and in your vacuum.

One feature of these bags that we truly loved is their spring-loaded, self-sealing collar which is located at the bag’s opening. Anytime you open the cover of the vacuum to expose the bag, the collar snaps shut sealing the bag and preventing any of the dust from escaping. We loved our virtually dirt free experience when changing the bag.

Using our particle scanner, we saw the particles per cubic foot coming from the exhaust of the vacuum actually decrease from our readings of the air in the room.

While the Miele S4212 Neptune vacuum doesn’t filter as well as more expensive Miele models that we have tested with HEPA filters and zero particle emissions, it still does a fantastic job and purifies the air as you clean. Also, you can purchase an active HEPA filter for this model.

Suction Strength

Miele S4212 Neptune ControlsDon’t let the size of this machine fool you, this baby can suck! With over eighty inches of waterlift, the Miele S4212 is powerful. Waterlift is the measurement used to test the strength of suction produced by a motor.

The Neptune has six settings of strength ranging from 300 to 1200 watts of power. The first setting is for curtains and lightweight fabrics. The second setting is for upholstery and cushions, the third setting is for thick pile carpets, rugs and runners.

The fourth setting is for energy saving daily vacuuming with a low noise level. Setting number five is for lightly soiled, textured carpets and the last setting is for textured hard flooring, and intensive cleaning of carpets.

Attachments / Onboard Tools

Miele S4212 Neptune AttachmentsThe Miele S4212 Neptune vacuum comes with three on-board attachments and an extension wand. A crevice nozzle, dust brush and upholstery tool are stored in a tool caddy that clips to the base of the hose where it attaches to the canister.

The stainless steel extension wand connects to the handle and the other attachments including the turbobrush and the parquet tool.

Crevice nozzle

The crevice nozzle is five and three-quarters inches long with the tapered end measuring one half inch. The length of the tool was limiting for getting deep into very tight places.

Dust brush

The dust brush has a one inch opening surrounded by one half inch of natural bristles. The brush rotates three-hundred and sixty degrees to give you a variety of angles while cleaning.

The natural bristles were gentle enough to use on wood surfaces without scratching. This brush worked great dusting everything from furniture to delicate decorations.

Extension wand

The extension wand is a convenient tool to use when cleaning hard to reach places. The wand measures twenty-three and three-quarters inches and extends to forty-one inches. There is a small button located at the top-back of the wand that controls the height of the wand.

One nice thing about this vacuum is the ability to adjust the wand to get to the perfect height for a variety of users and applications.

Upholstery tool

This tool is five inches long by one and one half inches tall with a one half by five inch opening. There is a strip of lint fabric across the top and the bottom of the opening. We found this feature especially helpful in capturing pet hair and lint while cleaning our furniture.

Ease of Use

Cord management and Length

Miele S4212 Neptune Cord RewindWe measured the cord to be seventeen feet and 6 inches long. However, the Miele Neptune has an operating radius of twenty-nine and one half feet.

Miele performs an interesting test on their vacuums called a Cable-Pull Test. In this test, the power cord is pulled out and retracted over 10,000 times as a part of their very aggressive quality assurance exam.

While we didn’t pull out and retract the power cord anywhere near that many times, we did find that it always operated smoothly and never got hung up when retracting. Miele reported that the Neptune aced their test.

Hose Management and Length

Measuring at six feet long, the hose is blow molded and flexible. When kept to the side or behind us, the hose did not present an obstacle while cleaning.

It does curve out a great deal from the vacuum when the vacuum is in its parked position, but because it is flexible you can bend it when storing the machine if you are short on space.

Miele claims that they have some of the best hoses in the world. They subject each production lot to countless tests including an endurance test.

In this test, they hang a vacuum cleaner plus an eleven pound weight from the vacuum thousands of times and the hose must pass undamaged before being included in a Miele box. We bent, stepped on and twisted the hose and never saw or felt any indication that the hose couldn’t handle stress.

Floor Selection

Miele S4212 Neptune HardwoodThe Miele S4212 vacuum cleaner comes with two floor attachments. The Turbobrush plus is designed to be used on carpets. The Turbobrush features a rotating brush that’s activated by air drawn through the head. The parquet floor tool is for use on hard surface flooring.

The perimeter of the floor tool is surrounded by natural bristles that act as a broom to sweep up debris that is then sucked into the vacuum. Both tools attach to the telescoping wand and are secured by a small button that will need to be pressed in order to take them off again. In addition to the attachments, the Neptune also allows you to choose between six suction strengths.

Getting Started

The vacuum is intuitively packaged so from the moment you open the box to when the vacuum is ready to use take place over a matter of only minutes. You won’t need any tools to assemble the Neptune, everything simply snaps into place.


The very small canister contributes to the ease in which the canister can be carried between floors and rooms. We also liked the the zero turn radius wheels on the bottom of the vacuum which we felt made the vacuum trail behind us very smoothly as we cleaned as well as allowing the vacuum to handle corners better.

The Neptune’s handle is basically a curved stick that is located between the telescoping wand and the hose. The part that you grip seemed a little thicker than other handles we have used and there wasn’t any finger grips for comfort.

Additionally, we felt that it caused a little strain on the wrist to keep the Turbobrush steady on carpets, although not nearly as much as other pivoting handled vacuums we have used.

We really enjoyed being able to control the power and cord rewind with just a tab of our foot. Both controls were very easy to use.

While many features of this machine are operable from a standing position, you will need to be able to bend almost to the floor to reach the attachments, control the suction strength, grab the power cord and changed the filters.

Ease of Use on Stairs

Miele S4212 Neptune on StairsWe found that using the Miele S4212 on stairs was very easy. The Turbobrush was narrow enough to fit on the staircase so you have the option of vacuuming from a standing position with the Turbobrush or you can use an attachment on the handle for a little more control.

Miele offers attachments designed specifically for use on stairs, but we did not have one for testing.

At only eleven pounds, carrying the canister by the handle located on top of the canister up the stairs as we vacuumed was easy to do.


The Miele Neptune is a petite vacuum. It won’t take much room to store and can be put away in the upright or flat position. There are storage holder slots located on the side and bottom of the vacuum.

The parquet and Turbobrush tool have a ridge that slides into these slots keeping the handle upright rather than having to lay it on the floor. We found the holders very convenient for both storage and mid-cleaning pauses.


We found the Miele S4212 Neptune to be impressively quiet for a vacuum, let alone a vacuum with this powerful of a motor. Miele contributes this to a thoughtfully designed motor suspension and unique motor seal.

Holding our decibel meter at chest level, the vacuum registered at an average of 72 dB. We could communicate over the sound of the vacuum without having to shout.


Miele S4212 Neptune Vacuum BagThis little machine does a great job cleaning without requiring a lot of maintenance. The AirClean filter will need to be changed every fifth time you change your dust bag and a filter conveniently comes in a box of bags so you don’t have to worry about purchasing it separately.

The bag will need to be replaced as it becomes full. We liked the dustbag indicator, located just above where the hose connects to the canister, that took all the guesswork out of determining when it was time to change the bag.

The pre-motor should also be cleaned every time you start a new box of bags. This filter will need to be cut to size and has guiding lines to insure you get the proper fit for your model. A box of four bags and two filters costs around nineteen dollars.

Value for your money

The Miele S4212 Neptune canister vacuum is a very impressive machine! The vacuum seemed sturdy and well built. While we were unable to test the longevity of this machine, we believe Miele’s claims that this vacuum will last for fifteen to twenty years.

Ranging in price from $400 to $599, the Neptune is more expensive than your typical vacuum. However, after using the Neptune and putting it through VacuumWizard’s arduous testing process, we feel that it is well worth the money.

This vacuum is an investment, but it will last for years to come and can handle such a diverse set of cleaning needs that you will be able to avoid purchasing multiple cleaning instruments.

Final Vacuum Verdict

Because of its condensed size and the smaller clearing path of the turbobrush, we would highly recommend it to someone with a carpeted smaller home or apartment or someone who doesn’t have a a large area of carpet to clean.

We also recommend the Miele S4212 Neptune vacuum to someone who suffers from allergies.

While it doesn’t have zero particle emissions like some Miele’s more expensive series, it still does a great job of purifying the air as it cleans and capturing particles and allergens.