Skip to main content
Sealy Harlow Ortho Plus Mattress

Sealy Harlow Ortho Plus Mattress

4.21 (112 reviews)
  • In-stock
  • Finance available
  • Free delivery
  • Returns

From £299.00 , last checked

BedBoy earns a commission on outbound retailer links. Editorial scoring is independent of commission rates. How this works →

BedBoy Score

A composite score drawn from aggregated customer sentiment across verified reviews, with construction-type benchmarks for categories where reviewer commentary is limited. See our scoring methodology.

3.5/5
BedBoy Score
across 2 measured categories

Per-category breakdown below. The composite is the unweighted mean of every scored category, rounded to one decimal place.

Strongest on customer sentiment; weaker on retailer guarantee.

  • Customer sentiment 4.2/5 Show evidence for Customer sentiment

    Customer sentiment scored 4.2/5 from an average star rating of 4.21 across 112 verified reviews.

  • Retailer guarantee 2.7/5 Show evidence for Retailer guarantee

    Retailer guarantee scored 2.7/5: 30-day money-back guarantee, 1-year manufacturer warranty (brand pass-through up to 10 years), and paid collection of large items. Sub-scores: trial 3.0/5, warranty 2.0/5, returns 3.0/5.

  • Comfort Rarely mentioned Comfort: Rarely mentioned. Not scored on this product.
  • Edge support Spec unavailable Edge support: Spec unavailable. Not scored on this product.
  • Motion isolation Spec unavailable Motion isolation: Spec unavailable. Not scored on this product.
  • Heat retention Spec unavailable Heat retention: Spec unavailable. Not scored on this product.
  • Value Rarely mentioned Value: Rarely mentioned. Not scored on this product.
  • Pressure relief Spec unavailable Pressure relief: Spec unavailable. Not scored on this product.
  • Durability Spec unavailable Durability: Spec unavailable. Not scored on this product.
  • Off-gassing and setup Spec unavailable Off-gassing and setup: Spec unavailable. Not scored on this product.

Brand
Sealy
Retailer
Mattress Online
Delivery time
Good
Customer sentiment
Excellent
Guarantee
Excellent

About the Sealy Harlow Ortho Plus Mattress

Last checked

Buyers looking at the Sealy Harlow Ortho Plus are looking at an old-school firm orthopaedic mattress rather than a cushioned pocket-sprung hybrid. Its support comes from Sealy’s PostureTech Core Support spring system, a coil-based unit designed to firm up as more load is applied, with tufting pulling the surface tighter and soft white fibres adding only a modest comfort buffer above it. Honest spec for the price tier. The orthopaedic feel here is achieved through spring tension, tufting and a relatively simple fibre layer, not through zoned pocket springs, latex, or a thick foam pillowtop, so the support is broadly firmer and more uniform than the more body-contouring feel found in memory-foam hybrids or the £700-plus pocket-sprung tier. At 26cm deep it has decent visual substance, especially on a low bed frame, and the damask cover sits in the traditional mattress register rather than the stretchy, sink-in surface used on many foam-led models. The single-sided build keeps maintenance simpler, but it also means rotation matters more because there is no second sleeping face to share wear. The 24kg double and 27.5kg king weights are manageable for two adults, while the 5-year guarantee and National Bed Federation approval keep the specification credible rather than flashy.

Back and front sleepers are the clearest match here, particularly those who dislike dipping into a mattress and want a flatter, more braced sleep surface. Owners repeatedly describe good back support, better comfort after aches or sciatica flare-ups, and a firm feel that still has enough surface cushioning to avoid feeling bare and board-like; the fibre comfort layer in the spec fits that feedback better than the occasional owner reference to memory foam, which is not listed in the supplied construction. Firmness is not read identically by everyone. Several substantive comments call it very firm and supportive, while a smaller but noticeable strand says it feels softer than expected, so buyers wanting an extra-hard orthopaedic slab may find the marketing stronger than the bedroom reality. Side sleepers with sharper shoulders or hips should be cautious, because the same tufted, tension-led build that helps back support gives less pressure relief than a deeper foam or latex comfort layer. For couples, the coil support and customer praise for edge stability are useful, but this is still not a pocket-sprung design, so movement isolation is unlikely to match individually wrapped springs when partners differ in weight or turn frequently. It suits firm-mattress buyers prioritising back support, UK-made construction and traditional breathability; those wanting plush side-sleeper cushioning, precise zoning, or low-disturbance couple support are better served by a pocket-sprung hybrid or a higher-spec foam comfort build.


Pros and Cons

Pros

  • Offers excellent support for the back, especially for those with back issues.
  • Firm feel helps reduce tossing and turning during the night.
  • Edge support is strong, providing stability when sitting on the mattress edge.
  • Constructed with durable materials, indicating long-lasting quality.

Cons

  • Some find it firmer than expected, which may not suit all preferences.
  • A few report that it feels softer than anticipated despite being marketed as firm.
  • Handles on the mattress can be inconvenient for some users.
  • Limited adjustability may make it unsuitable for side sleepers who prefer softer options.

Price Tracker


Giselle Green Written by Giselle Green, Editor in Chief

Last checked by Giselle Green on . Scoring follows our scoring methodology.


Specifications

Manufacturer specifications without the jargon, easy to scan and compare.

5 year guarantee

A 5 year guarantee is longer than the industry standard and gives confidence that both the supplier and retailer have confidence in the product they sell. After all, if it goes wrong through a manufacturing defect in this time, they will be the ones on the hook! Sleep soundly with the confidence that you will not be left out of pocket through this period. A win for the consumer.


Depth: 26cm

Impressively deep at 26cm, this specification is suggestive of a more luxurious sleep surface, potentially providing greater comfort and support due to the possible inclusion of additional layers. However, it may require deeper fitted sheets, which could be an additional consideration for potential buyers when thinking about overall ease of use and maintenance.


Approved by the National Bed Federation

The independent seal of approval from the National Bed Federation assures meticulous standards of manufacturing. With a rigorous assessment of quality, durability and safety, such an endorsement means you're getting a product that meets top-class industry standards, contributing to more sound and relaxed slumbers.


Orthopaedic Support

This king-size sanctuary of comfort grants sterilised hypoallergenic filling that ensures sleep is not disrupted by common allergens. Furthermore, an impressive tally of 2000 individually nestled springs provides the spine with correct alignment, tackling backaches and promoting a healthy sleeping posture.


Fire Resistant

Ensuring safety during your peaceful slumber, fire resistance is a crucial feature that reduces the risk posed by potential accidents involving flammable materials. Furthermore, it demonstrates the manufacturer's commitment to adhere to strict safety standards, prioritizing your well-being over all else.


PostureTech Core Support Springs

Featuring a proprietary PostureTech Core Support Springs system, this technology ensures an equal distribution of weight across the entire sleep surface. As such, it can help promote correct spinal alignment and alleviate pressure points, thereby promoting a more restful and comfortable night's sleep.


National Bed Federation Approved Brand

Receiving approval from the National Bed Federation indicates that the product meets specific industry standards and quality benchmarks. This approval serves as a reassurance of the product's reliability and durability, though discerning buyers may still want to consider personal comfort preferences.


26cm deep

A mattress with a depth of 26cm assures a medium-thick construction, offering a harmonious blend of support and comfort. Consequently, sleepers can anticipate a balance between plush comfort layers and robust supporting springs or cores, without any compromise on overall longevity.


Soft White Fibres

Incorporating soft white fibres into the design equates to enhanced breathability and temperature regulation within the sleep surface. This, in turn, contributes to a sleeping environment that stays fresh and cool, promoting a more restful and comfortable night's slumber.


Firm

Firmness in a mattress indicates robust support for your spine, reducing the risk of back pain and contributing favourably to your posture. Still, it might not be suitable for those who prefer a softer surface or side sleepers, who could find such solidity uncomfortable.


Damask cover

The damask cover provides a plush, luxurious feel to your bed while still being durable and easy to clean. With a traditionally elegant design, it adds a touch of timeless aesthetic to your bedroom.


Handcrafted in the UK

Wow! If you're looking for a high-quality mattress that is handmade in the UK, then this is one to watch. This mattress is made with high-quality materials and tested to ensure quality.


Made in the UK

This 100% UK made product is the perfect choice for a home with a sense of individuality. Sleep in comfort with the knowledge that you'll waking up refreshed and ready for another day.


Single-sided

Unlike double-sided mattresses that require flipping, a single-sided mattress only needs to be rotated periodically, making maintenance easier.



Frequently Asked Questions For The Sealy Harlow Ortho Plus Mattress

The questions below are the most common ones BedBoy readers ask when comparing products in this category. Contact the editorial team with a different question, quoting P771 in the subject line.

The firmness of this mattress is consistent throughout due to the PostureTech Core Support coil spring system in place. This technology allows the mattress to adapt to any applied weight and movement, becoming gradually firmer.
Sure, the cover of this mattress is made from damask, a finely woven fabric known for its durability and softness. It features a cool touch; so, it doesn't retain heat, ideal for maintaining a comfortable sleeping temperature.
This mattress has been designed as single-sided, so there's no need to flip it over. However, it's recommended to rotate the mattress every few months for maintenance and even wear.
The Sealy Harlow Ortho Plus Mattress does have a unique PostureTech Core Support coil spring system that's designed to provide excellent support, particularly to the heavier parts of the body. However, it's the whole mattress that benefits from this support, not just the middle. As you use the mattress, it becomes gradually firmer, adapting to your body weight and movement. - Gary
This mattress does promise firmness throughout, however it does seem from some customer feedback that the edges may be softer than the centre. The firmness comes from the unique PostureTech Core Support coil spring system, which provides excellent support but the edges may not hold shape as well as the middle.
Stomach sleepers could suit it well because the firm surface helps stop the middle of the body dipping. It is a better fit if you prefer being held up on top of the mattress.
Back sleepers are the strongest match, especially if you want your pelvis kept level. The spring unit gets more resistant under load, so average-to-heavier sleepers should feel the clearest support.
Side sleepers may find it too firm, particularly if they have broader shoulders or hips. There is limited sink for pressure points, as the comfort layers are fairly conservative rather than deeply contouring.
It is single-sided, so you rotate it rather than flip it. The mattress is 26cm deep and has a tufted finish, which helps maintain its firmer, held-up feel.
It is rated 5 out of 5, with a taut, traditional orthopaedic feel. Expect firm push-back from the springs rather than a plush or sinking surface.
It is less likely to feel swampy than a mattress with thick memory foam. The Soft White Fibres and damask cover are simple, breathable-leaning materials, though the feel is more practical than airy or luxurious.


Reader reviews of the Sealy Harlow Ortho Plus Mattress

BedBoy publishes reader-submitted reviews to broaden the sentiment sample. Reviewer purchase status is not independently verified at submission. For verified-purchase ratings, see the Trustpilot block below. Submit a review, quoting P771 in the subject line.

Generic placeholder avatar for customer review
Tuscany via bedboy

It offers great support for the back, though its not as firm as expected. Nonetheless, it's generally comfortable for a nights sleep.


Generic placeholder avatar for customer review
Guillaume via Mattress Online

Extremely comfortable and great quality


Generic placeholder avatar for customer review
Ian via Mattress Online

Super good. Love it.


Generic placeholder avatar for customer review
June via Mattress Online

Excellent mattress


Generic placeholder avatar for customer review
Ender via Mattress Online

Really good value for money you pay


Generic placeholder avatar for customer review
Nicola via Mattress Online

Great firm mattress. Well made and comfortable.


Generic placeholder avatar for customer review
Margaret via Mattress Online

Ordered another one .Arriving Tuesday


Generic placeholder avatar for customer review
Randolph via Mattress Online

Good quality mattress.


Generic placeholder avatar for customer review
James via Mattress Online

Good solid mattress. The memory foam takes some getting used to. I dont overheat and is comfortable. Aired as as described and on laundry day and no funny or lingering smell. I have has sealy before and wont change now or in the future.


Generic placeholder avatar for customer review
Bob via Mattress Online

Well made, good quality comfortable.


Generic placeholder avatar for customer review
Ross via Mattress Online

Firmer than I expected it to be. It is a very firm mattress. You don't sink into it. I like this and my back has been better. Feels like a quality product that will last. I was worried that I wouldn't like the memory foam but I can't really feel it, it just feels soft. Great mattress if you like a firm one


Generic placeholder avatar for customer review
steven via Mattress Online

Good support.


Generic placeholder avatar for customer review
JUDITH via Mattress Online

The handles! Quite amazing how few mattresses include them.


Generic placeholder avatar for customer review
patricia via Mattress Online

nice looking very good quality and very firm


Generic placeholder avatar for customer review
CHRISTOPHER via Mattress Online

Improvement Points: too firm


Generic placeholder avatar for customer review
Helen via Mattress Online

Very firm and supportive


Generic placeholder avatar for customer review
Gavin via Mattress Online

Very supportive, great price


Generic placeholder avatar for customer review
Karen via Mattress Online

Really comfortable mattress and looks good. One happy Son.


Generic placeholder avatar for customer review
Nicholas via Mattress Online

matress is firm and comfortable, very good value for money


Generic placeholder avatar for customer review
Peter via Mattress Online

Feels a quality product and well made.



Verified retailer reviews

Independent Trustpilot reviews of Mattress Online.


Customers Went On To Purchase

A few more options from the retailer that customers loved.


Not sure which mattress fits? The 60-second BedBoy quiz narrows the field by sleep position, build and budget. Take the mattress finder quiz