Internet #303519511

Model #SM-WC424

Store SO SKU #1002814575

Concealed In-Wall Toilet Carrier System 2 in. x 4 in. for Wall-Hung 1.28 GPF Dual Flush Toilet Tank Only in Black

  • In-wall system leaves floor free with a sleek and stylish look
  • ECO friendly with superior flush performance
  • Adjustable height allows bowl setting to personal preferance
  • See More Details

Frequently Bought Together


Product Overview

A great choice for bathrooms with limited space. With the carrier concealed in the wall, only the bowl and actuator plate are mounted to the wall, resulting the sleekest design that is incredibly easy to clean. When choosing a wall hung toilet, you will need to select a carrier matching your construction studs, either 2 in. x 4 in. or 2 in. x6 in.
  • Installed on 2 in. x 4 in. studs behind the wall for thinner residential walls
  • Dual flush with high-performance gravity offers you the choice of full or partial 0.8 / 1.28 GPF (gallon per flush)
  • Large flush actuator plate opening can be removed for easy access to the inner tank plumbing and speedy valve
  • Adjustable height allowing the bowl to be set anywhere from 15-3/8 in. to 28-1/2 in. from floor

Info & Guides

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Flush Valve Size (in.)
Product Depth (in.)
4 in
Product Height (in.)
Product Width (in.)


Color Family
Commercial / Residential
Insulated Tank
Flushing Technology
Gravity Fed
Flushing Type
Dual Flush
Gallons Per Flush
No Additional Items Included
Cast Metal
Models used with
SM-WT449, SM-WT450, SM-WT450MB, SM-WT455, SM-WT660
Product Weight (lb.)
Trip Lever Location

Warranty / Certifications

Certifications and Listings
No Certifications or Listings
Manufacturer Warranty
1 Year Limited

Questions & Answers


where to get the replacement parts for the inside unit?

Asked by JC November 10, 2020

Will this work with wall mount toilets of other brands? Are wall cisterns interchangeable?

Asked by Potato September 18, 2020

They are of a standard design. Kohler, Toto will also fit. The Swiss Madison porcelain included a soft close seat and is much less expensive but quality is still not on par with the more popular/higher priced brands but they do not include the seat. Final cost was several hundred dollars less for each.

Does this kit include the toilet?

Asked by Raf August 17, 2020

The bowl is sold separately as well as the wall plate (flush buttons). Most wall hung brands will fit. Toto, Kohler as well as Swiss Madison. The Swiss Madison bowls that we purchased did come with the seat included.

Where do you get the shut-off valve for this system? I understand it's BPT?

Asked by dougiejones June 2, 2020

Answering my own question. Never mind. Now that the item arrived I see that the valve is included. Looks like it's not possible to correctly install the included valve from the inside of the tank - you have to attach the valve to the tank first and only then thread the copper fitting to the top of the valve - so you have to have access to above the tank while installation.

when will 4 be available to purchase?

Asked by Liza April 23, 2020

It appears that they are out of stock. Calling the Pro Dest is a great way to get an answer because they have a direct number to the distributor. Also 1-434-623-4766 (Swiss Madison) customer service can help. Be sure they are the correct size. A 2x4 carriage will fit between both 2x4 and 2x6 studs but a 2x6 will only fit 2x6 framing. Just a note, the drain pipe is very tight dropping through 2x4 plate. Also the 2x6 carrier is available if you do have 2x6 framing.

Is this toilet carrier system compliant with ASME code?

Asked by forever0 April 6, 2020

No, it is not ASME code compliant.

Is this ok to use in northern states (Michigan) with cold winters? It would be mounted in an oute...

Asked by Freezing April 2, 2020

Hello, Please speak with your plumber or contractor for advice on properly winterizing our toilets. Thank you, The Swiss Madison Team

Does anyone had this installed behind dry wall for any length of time and did it hold up? We just...

Asked by Karin March 23, 2020

We have been using our three toilets for over a year now with no issues. I mounted the "feet" with stainless steel lag bolts and four lag bolts into the studs. I also doubled the studs (cheap piece of mind).

Is 235 the lowest you can go in need to buy 2

Asked by Antonio January 27, 2020

I am not a Home Depot employee but I do know that the mark up in this is very low. I am a builder and they do what they can on volume bids but I didn't catch any break on the three carriers, bowls and flush plates I purchased last year. The Toto brand is nearly three hundred dollars more and the bowl does not include the seat like the Swiss Madison does. The flush plate is around half the cost as well. One thing I would say is that the Toto in-wall toilets are easier to install. I would not recommend installing them on your own unless you are an experienced plumber or handyman. For a remodel, the toilet drain must be relocated for obvious reasons.

Reviewing the installation instructions, I find it somewhat difficult to decipher exactly what so...

Asked by madman January 11, 2020

The instructions are vague. I wrote a review stating this but for some reason it was never posted. The 3" drain pipe is not standard and they recommend sanding it until it fits. I used a 3" fernco rubber fitting and it works great. The in-tank supply valve is BPT(European) not NPT so either needs to be tapered cut to fit NPT or find a British pipe thread fitting. The frame should be mounted between doubled up 2x4 or 2x6 studs. The bowls sizes were not consistent in the three units I installed. I put a temporary piece of sheetrock up and test hung the bowls for proper install height and test the inlet and drain pipe length before I cut to fit. I recommend not using the measurements given in the install instructions. The pre cut foam pad is placed before sheetrock. I hope this helps.

Concealed In-Wall Toilet Carrier System 2 in. x 4 in. for Wall-Hung 1.28 GPF Dual Flush Toilet Tank Only in Black - page 2

Customer Reviews

  • 9 Customer Reviews
  • 4.5 out of 5 stars overall
80% of customers recommended.
Overall Ratings
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Great for our application, especially adjustable height
We had to install in an attic master bath. This really helped with our limited plumbing clearances. The previous toilet was traditional floor mount and had an ugly raised platform for plumbing to clear the floor. We're also short - typically I can nearly swing my legs when sitting, so we were able to adjust this to the lowest clearance and voila! I can touch the floor! Contractor had no trouble installing and this was the first one he'd ever done. Quality is mostly plastic, but the savings/value between this and a high end brand is pretty exceptional. Be careful when ordering that you're buying for correct stud width. This is 2x4 as we have an old house. You'll need a different version for 2x6 framing.
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Cool product and space saver unit hides behind the wall....
Cool product and space saver unit hides behind the wall. Would get same unit for the next bathroom project.
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Response from Swiss Madison TeamJune 2, 2020
We apologize you are unhappy with our product! If there is any technical assistance, or information we can offer you, please do not hesitate to reach out to our customer service team. We will be glad to assist you with any troubles you may have. Our contact information is listed on Thank you, The Swiss Madison Team SwissMadison
Excellent quality , I am looking forward to finish the...
Excellent quality , I am looking forward to finish the install with my sleek looking wall mounted toilet from Swiss Madison.
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We have had it installed for about 3 weeks now. So far, so good. What is odd is the description...
We have had it installed for about 3 weeks now. So far, so good. What is odd is the description (only in black). Since we put it inside the wall the color wouldn't matter.
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Rating provided by a verified purchaser...
Rating provided by a verified purchaser
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Great product, pairs perfectly with their wall hung toilet model. Brings a nice European flair in...
Quality :
Value :
Ease of installation :
Great product, pairs perfectly with their wall hung toilet model. Brings a nice European flair into my home. Love it.
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Smart design that was very easy to install with no...
Smart design that was very easy to install with no hassles so far.
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This in-wall carrier is easier to install then other wall hung toilets and the Swiss Madison qual...
This in-wall carrier is easier to install then other wall hung toilets and the Swiss Madison quality is superb. Looks absolutely beautiful! I am now going to replace all our other floor toilets with wall hung.
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