Miele Delphi Canister Vacuum


 Avg. consumer rating = 90/100 

The Miele S2121 Delphi canister vacuum is designed for bare floors and low-to-medium pile carpet.  It has recently been renamed to the "Miele Classic C1 Delphi Canister Vacuum Cleaner".  It is now blue in color but otherwise the same machine. It has variable suction as well as a host of other features. In addition, high consumer ratings suggest that it is indeed well-liked by its owners. The vacuum is also quiet, lightweight and not too large. However, it does not come with a specialized bare floor tool (like its more expensive brother, the Titan) and some owners feel this is a drawback.

The Delphi is part of the S2 series of Miele canister vacuums and it is a mid-range S2 vacuum.  The S2 series contains the following machines:

Olympus (approx cost: $330)
Capri (approx cost: $399)
Delphi (approx cost: $499)
Titan (approx cost: $599)

Note: there is also another S2 vacuum called the HomeCare but it is not too popular and we don’t see it on the market much.  The four machines listed above are much more widely available.

The Delphi is the least expensive S2 that includes an electric hose and electric wand (the Olympus and Capri are less expensive vacuums but they do not have an electric hose or wand).  An electric hose/wand allows the vacuum to use motorized floor tools which tend to perform better on carpet.

Consumer Ratings & Insights
Over 100 consumer ratings were found for the Delphi and these are contained in the table below.  When averaged these generate a score of 90 out of 100 or about 4.5 stars out of 5.  You can compare this score to others in our Miele vacuum ratings table or our Canister vacuum ratings table.

Ratings Updated October 2017
 Source  Consumer Ratings  #Ratings
 Amazon  4.5 stars out of 5  90
 Mr Vac & Mrs Sew  5 stars out of 5  6
 Bed Bath & Beyond  4.2 stars out of 5  10
 Bloomingdale's  5 stars out of 5  2


 A review of owner comments yields the following Delphi likes and dislikes:

- Quiet operation
- Very lightweight
- Variable suction
- Small footprint for easy storage

- No bare floor brush
- Power cord is a little short
- Canister can sometimes tip over

The general consensus on the cleaning ability of the vacuum is that it does a very good job on both carpet and bare floors, however there are several suggestions that bare floor cleaning would be better and easier with a specialized floor tool.  In order to clean bare floors with the Delphi the motorized floor tool is used but with the brushroll turned off.

Miele S2 on Carpet
Miele S2 and Electro Comfort Brush on carpet

While most owners wish the Delphi came with a specialized floor tool there are at least a few that feel the ability to clean both carpet and bare floors with a single tool is a benefit. Having a single tool saves the time of switching from one floor tool to another – especially if you have a lot of areas of both carpet and bare floors. 

There are a few reports that the floor tool can get a little difficult to push on higher pile carpet, especially if the suction is on high.  Indeed there is no nozzle height adjustment on the vacuum (although it has a floating head).  But some owners say that dialing down the suction helps.
There is almost unanimous agreement that the vacuum is very quiet, although the volume goes up a bit when using the accessories – smaller tools tend to create more suction noise.

You can read more Delphi owner comments on Amazon if you wish.

A little bit about Miele canister vacuums
Before discussing more about the features and specifications of the Delphi we’d like to say a few words about the many Miele canisters on the market today.  Miele is often releasing new vacuum series and retiring others. Presently their canister stable includes the S2’s, the S6’s and the S8’s. The S6 vacuums were released in late 2011 while the most recent series is the S8’s. The S2's are the most affordable canisters, and the S8’s are the most expensive with top end models going for as much as $1500.   The S5’s have been retired but they are still often available online.

With four series of canister vacuums and many models within each series, there are a tremendous number of vacuums to choose from. In fact there are so many that potential buyers are often confused.  In our opinion before buying a Miele canister it is best to first ask yourself a few questions:

1) What kind of floor cleaning do you intend to do?
Bare floors only? Bare floors and low pile carpet? Bare floors and medium/high pile carpet? This is a very important consideration as Miele canisters are coupled with all manner of bare floor and carpet tools. You want to ensure your model will do the job for your flooring.  Probably the most common complaint from Miele canister owners is that they got the wrong vacuum for their floor types (although most floor tools can be purchased separately). As the Delphi is in the S2 series consider the following:

S2 Olympus
• Non-electric, SBD350-3 Classic Combination carpet/smooth floor tool
For all smooth flooring and low-pile carpeting

S2 Capri
• Non-electric, STB205-3 Turbo Comfort Turbobrush
For low to medium pile carpet
• Non-electric, SBB-3 Parquet Floor Brush
For wood and tiled floors.

S2 Delphi
• Electric, SEB 217-3 Electro Comfort
For low and medium-pile carpet care, and smooth flooring.

S2 Titan
• Electric, SEB 217-3 Electro Comfort
For low and medium-pile carpet care, and smooth flooring.
• Non-electric, SBB-3 Parquet Floor Brush
For wood and tiled floors.

S6 floor tools are similar if not exactly the same but the S8’s have a few fancier floor tools.

2) What level of filtration would you like?
Basic? HEPA? You can also get each level of filtration with activated carbon for odor removal – which can be a nice feature if you have pets. And some canisters (like the S5’s, S6’s and S8’s) have a special sealed system that ensures unfiltered air doesn’t leak out through the vacuum body.  The S2’s do not have sealed system construction (you can read more about this and HEPA filtration in our HEPA filtration article).

S2 Olympus
• AirClean Filter (94% of particles down to 0.3 of a micron).
Will accommodate optional HEPA filter

S2 Capri
• AirClean Filter (94% of particles down to 0.3 of a micron).
Will accommodate optional HEPA filter

S2 Delphi
• AirClean Filter (94% of particles down to 0.3 of a micron).
Will accommodate optional HEPA filter

S2 Titan
• HEPA filter (99.95% of particles down to 0.1 microns).

3) How quiet do you want the vacuum to be?
All Miele canister vacuums are fairly quiet but some series have additional sound insulation for even quieter operation. According to Miele’s website the S6’s and S8’s use the new low noise vortex motor.

4) Do you want controls on the vacuum handle?
Some premium S5 and S8 models have suction controls, a standby button, brushbar on/off controls, etc on the handle. Other series and models may not have all of these features, and most controls are on the canister body.   The Delphi has brushbar on/off controls on the vacuum handle.

5) Is bag size an issue to you?
Larger bags do not have to be replaced as frequently. The S6’s have smaller bags than the S2, S5, S8’s.  The S2’s have a large 4.76 quart dust bag.

6) Is on-board attachment storage important to you?
The S5 and S8 models have an attachment storage compartment in the canister itself. The S2’s and S6’s allow you to clip the attachments to the hose. A number of consumers report that attachments clipped to the hose sometimes get in the way.

7) Are you concerned about vacuum reach?
The S5, S6 and S8 series have a cleaning radius of 33 feet.  The S2’s are only 29.5 feet.

There are a few more features that can be considered but those highlighted above should help you more quickly narrow down the series and models that best match your needs. And here’'s a little secret – the Delphi is $100 less than the Titan, but you can buy the SBB-3 Parquet Floor Brush for about $60 on Amazon (check it out here if you wish).  This will give you the same floor tools as the Titan for less than the cost of the Titan.  Bear in mind however that the Titan includes HEPA filtration, but if you are only concerned with floor cleaning ability then you may be better off with the Delphi and buying the additional floor tool.

The S2121 Delphi
The Delphi is powered by a Miele 1200 watt vortex motor.  These are designed in Germany and are still manufactured by Miele in Germany.  Suction on the vacuum is controlled by a dial on the canister body with 6 settings:

1 Curtains and fabrics
2 Upholstery and cushions
3 Carpets and rugs
4 Low-pile carpets
5 Tiles and hard floors
6 Light vacuuming with minimal sound


Delphi Rotary Suction Dial
Rotary Suction Dial with 6 Settings


The electric floor tool (SEB 217-3 Electro Comfort) is designed for low and medium-pile carpet as well as smooth flooring.  The floating head adjusts, to some extent, for different carpet heights – although there is no manual height adjustment.  The brushbar can be turned on and off via controls on the vacuum handle.  Generally the brushbar is ON when cleaning carpet and OFF when cleaning smooth flooring.  The Electro Comfort has a swivel neck which makes it fairly maneuverable and easy to turn.

The Electro Comfort also has rubber wheels that ensure it does not scratch delicate flooring.  In addition, there is an electric overload switch built into the powerhead.  This switch will turn the powerhead off immediately if the motor starts to overload – which can occur if something gets caught in the brushbar or if there is some other kind of blockage.

Additional tools that come with the vacuum include:
- upholstery tool
- dusting brush
- crevice tool

There is on-board storage for these three tools in the form of a “tool storage clip”.  This clip attaches to the hose but some owners feel it isn’t the best way to store the tools and that it sometimes gets in the way.

The S2121 Delphi also comes with a stainless steel, telescopic wand.  The wand is electric in that it provides electricity to the powered floor tool.  The hose on the Delphi is electric as well and it is 5.5 feet in length.  The hose, wand, tools, and vacuum power cord provide a cleaning radius of 29.5 feet.  The power cord is automatic rewind, a popular feature with many owners.

Three caster wheels that can each rotate a full 360 degrees allow the canister to easily follow along while you vacuum.  It also turns smoothly.  The casters are made of durable rubber so they are sturdy but still don’t mar your floors.  There are some comments however that despite the 360 degree casters the canister will sometimes tip if you pull it around a tight corner or turn it too sharply.

The Delphi comes with an AirClean filter.  This level of filtration captures 94% of particles with a diameter of 0.3 microns or larger, but it is not as effective at removing allergens as a HEPA filter.  The vacuum will accommodate a Miele active HEPA filter should you wish to upgrade.   Miele states that you should change the filter about every 5 vacuum bags, and if you buy certified Miele vacuum bags they usually come in a package of 4 or 5 and include an AirClean filter as well as a motor protection filter.  The motor protection filter, or pre-motor filter as it is sometimes called, is standard on all S2’s and it protects the vacuum motor from dirt and dust. 

There is also a built in bag change indicator so you don’t have to continually check to determine if a new bag is needed (the indicator changes to orange when the bag is full).  Although we would highlight that the bag change indicator is driven off of airflow so it is possible for the indicator to turn orange as the result of an obstruction or partial obstruction in an area of the vacuum other than the bag – like the powerhead, wand or hose.

The vacuum bags used in this machine are type G/N AirClean vacuum bags and they have self sealing collars.  The self sealing collar snaps shut when the bag is removed from the vacuum and ensures no leakage of dust or debris.  The bags are the largest used in Miele canisters and have a volume of 4.76 quarts.

A built-in carry handle makes the Delphi very easy to move from place to place or even up and down stairs.  The vacuum body is very lightweight and it weighs only 9.5 lbs.  Many owners comment on the light weight of the unit.

Additional vacuum features include an 11 inch cleaning path width, a safety shutoff feature that will engage if the vacuum’s main motor starts to overheat, and a 7 year warranty on both the motor and casing.  There is however only a 1 year warranty on parts and labor.  The Miele S2121 Delphi is UL listed and CSA certified. 

Miele reports that the vacuum is designed to last for approximately 20 years of residential use.  Bear in mind that this calculation is the result of testing the vacuum for 1000 hours of use and taking an average annual use of 50 hours.  1000/50 = 20 year lifespan.

Vacuum Cleaner Manual
You can view a copy of the Delphi vacuum manual on the Miele website here.




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About Me


I'm Nigel Russco, a 50 year old professional engineer who loves to review vacuums, and I’ve been doing just that since 2008.  

I strive to write unbiased, intelligent vacuum cleaner reviews and I provide a score for each and every vacuum I investigate.  My goal is to help you find the best vacuum for your cleaning needs.

Also, watch my video reviews on the Vacuum Cleaner Advisor YouTube Channel.