Serta iComfort CF4000 Firm Mattress Review

Updated July 27, 2021

Serta iComfort CF4000 Firm Mattress

The iComfort CF4000 Firm mattress is the top-of-the-line firm model in the CF iComfort collection. It’s one of 6 beds available in their iComfort collection and it’s highly rated, as our test results confirmed.

Comfort Scale Rating

The CF4000 Firm mattress is a medium comfort that we rate a 5 on our 10 point Comfort Scale (a 1 is hard, 10 is softest.) This mattress comfort will appeal to most people because it’s not too hard or too soft, despite it being named a 'Firm'. This is really rather a medium-feeling bed based on our comfort testing which is a great feel for most people. If your preference is for a very firm or very soft bed, check out one of the other mattresses in the iComfort collection

iComfort CF4000 Firm Expert Video Review

Here’s our quick Video Review. It highlights the features, benefits, and our impression.

Pros & Cons

PROS CONS
  • Tested well demonstrating great support and contouring
  • Minimal motion transfer, you'll likely not feel your sleep partner's movements 
  • Well recommended for pressure relief and back support
  • Medium comfort appeals to most people
  • Premium materials including Air Support™ Foam 
  • Serta is a very popular Trusted Brand, in business since 1931 
  • Medium comfort may not be ideal for those looking for a very soft or a very firm feeling bed 
  • All foam mattress, no coils for added support if that is your preference
  • Not available in Twin or Full sizes
  • Not recommended for larger-sized side sleepers

View Bed


Pressure Test Results

We've pressure tested the iComfort CF4000 Firm mattress with small, average, and large body size people on their sides and on their back sleeping positions to see what kind of support and pressure relief you can expect. (Learn how we test.)  

For an all-foam mattress, this model performed very well, earning four out of six 'recommended' scores for its outstanding pressure relief and fantastic back support. Both the pressure relief and backs support a bed gives you are extremely necessary for good quality sleep. Too much pressure causes tossing and turning, while a lack of back support can cause stiffness and pain. Both lead to disturbed, uncomfortable sleep, which is detrimental for your body and mind.

When you consider these test result images keep an eye out for green areas where the pressure relief in the mattress is doing its job. The yellow areas show an increase in pressure and the red areas show where there's too much pressure.  

BACK SLEEPER SIDE SLEEPER
LARGE PEOPLE Largest 10% of adults 210-273 lbs Large back sleeper heatmap Avg Pressure: mmHg - Area: inches2 Large side sleeper heatmap Avg Pressure: mmHg - Area: inches2
AVERAGE PEOPLE Middle 50% of adults 134-218 lbs Average back sleeper heatmap Avg Pressure: mmHg - Area: inches2 Average side sleeper heatmap Avg Pressure: mmHg - Area: inches2
PETITE PEOPLE Smallest 10% of adults 111-135 lbs Petite back sleeper heatmap Avg Pressure: mmHg - Area: inches2 Petite side sleeper heatmap Avg Pressure: mmHg - Area: inches2
BACK SLEEPER
LARGE PEOPLE Largest 10% of adults 210-273 lbs Large back sleeper heatmap Avg Pressure: mmHg - Area: inches2
AVERAGE PEOPLE Middle 50% of adults 134-218 lbs Average back sleeper heatmap Avg Pressure: mmHg - Area: inches2
PETITE PEOPLE Smallest 10% of adults 111-135 lbs Petite back sleeper heatmap Avg Pressure: mmHg - Area: inches2
SIDE SLEEPER
LARGE PEOPLE Largest 10% of adults 210-273 lbs Large side sleeper heatmap Avg Pressure: mmHg - Area: inches2
AVERAGE PEOPLE Middle 50% of adults 134-218 lbs Average side sleeper heatmap Avg Pressure: mmHg - Area: inches2
PETITE PEOPLE Smallest 10% of adults 111-135 lbs Petite side sleeper heatmap Avg Pressure: mmHg - Area: inches2

The CF4000 Firm Features in Detail

iComfort CF4000 Firm Cutaway Image
  1. 1. Cool Touch Cover

    The cover for this mattress is cool-to-touch which gives you a cooler feeling to help you drift off to sleep. This is the first layer of several that works to provide you with a temperature-neutral sleep environment.

  2. 2. Carbon Fiber Memory Foam

    A  first-of-its-kind memory foam layer infused with carbon fiber for cooling as well as strength and resiliency. This system channels heat away from your body and it provides exceptional strength for back and neck support.

  3. 3. Deep Reaction™ Max Memory Foam

    This layer of Deep Reaction™ Max Memory Foam enhances the bed's heat dissipation and further enhances the overall comfort and support this bed offers. 

  4. 4. Air Support™ Foam

    The exclusive air-cushion technology in this foam layer moves with your body and smartly contours around it to help soothe pressure points and alleviate aches and pains.

  5. 5. Serta Foam Core

    The core foam upon which the rest of the foam layers rests. This foam is the firm part of the bed, it's the foundation for the comfort materials in the top part of the bed which also gives you conforming support

Comfort Depth Video

We measured how far your hips and shoulders sink into the CF4000 Firm mattress with different body types.

Aaron's Comfort View

Richard's Comfort View

Andrew's Comfort View

Warranty

The iComfort CF4000 Firm mattress comes with a 10-year warranty against factory defects.

Conclusion

The CF4000 Firm is one of two CF4000's at the top-end of the iComfort collection of 'CF' models. Despite this model being named a 'firm' our testing indicates that its comfort is more of a medium feeling mattress. While it's firmer than the CF4000 Plush it's nowhere near what we'd call a 'firm' feeling.  The three snowflakes stitched into the cover at the foot of the bed show you that this mattress has many layers of cooling materials.

 A layer of Carbon Fiber Memory Foam paired with the UltraCold System™ channels heat away from your body. More comfort is derived from the Deep Reaction™ Max Memory Foam. Serta's exclusive Air Support™ Foam contours to your body and helps relieve aches and pain caused by pressure points. This premium plush mattress is one of the coolest sleeping iComfort models ever.

These comfort materials helped this mattress earn a 'recommended' for four out of six body size/sleep position combinations during the pressure testing phase of our review process. The bed performed well for all back sleepers as well as the petite-sized side sleeper which is where the fourth recommendation was picked up. It's worth noting that this mattress also did earn a 'not recommended' score for larger-sized people who sleep on their sides, so I wouldn't suggest it for those who fit that category. The pressure relief is excellent in this bed is excellent and the back support is outstanding for most people. 

I don't make ridiculous money writing mattress reviews, I live paycheck to paycheck just like nearly everyone. I think that this bed, priced at $2,599 for a Queen size, is a pretty expensive buy. That said, for anyone who wants a medium comfort bed with all the trimmings, then this is one of the best mattresses you could get. If you still want one of these iComfort 'CF' models but can't afford the steep tab, check into one of the other models, the price swing is as large as $1,000!


View Bed

Serta iComfort CF4000 Firm Specifications:

Product Name
Queen Price

$2,599

Brand
Serta
Mattress Comfort
Medium-Firm
Comfort Scale Number
5
Coil Count
None
Coil Gauge
N/A
Height
13.5"
Comfort Padding Layers
Warranty
  • 10-year warranty against manufacturer's defects
  • No Flip, No Rotate
  • Non-prorated
Back Support System
  • Serta Balanced Support Foam
  • Deep Reaction™ Max Memory Foam
  • Serta Foam Core
Quilt Top of Mattress
Edge Support
  • yes
Recommended For Side Sleepers Who Weigh
  • 134-218 lbs
  • 111-135 lbs
Recommended For Back Sleepers Who Weigh
  • 210-273 lbs
  • 134-218 lbs
  • 111-135 lbs

About the Author, Dave Higgins

Dave has worked in the furniture business, focusing on mattresses, for over six years. He enjoys oil painting in the Impressionist style, playing guitar, and cooking for his family.  Dave also believes that English Bulldogs are the comedians of the canine world.

Mattress Comparisons

Compare Casper Mattresses Helix vs Tuft & Needle Mattress Review Purple vs Ghostbed Mattress Review Purple vs Nectar Mattress Review Casper vs Helix Mattress Review