Silentnight Healthy Growth Comet Eco Comfort Miracoil Mattress
The Silentnight Healthy Growth Comet is a single mattress built around Miracoil® springs and breathable EcoComfort Fibres™, with a quilted sleep surface on top.
- Zoned support for kids & teens
- Breathable fibres keep kids cooler
- 60-night trial & 5-year guarantee
£219
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Silentnight rates the Healthy Growth Comet Medium/Firm, which means it gives growing sleepers steady, supportive comfort rather than a soft, sink-in feel. At 21cm deep it's slimmer than many adult mattresses, though that's fairly typical for a children's design and makes fitted sheets easier to manage. Available in a UK Single, it sits at an accessible price point, and Silentnight backs it with a 60-night trial and a 5-year guarantee, so there's room to change your mind if it doesn't suit.
Mattress specifications
Firmness
Medium Firm
Type
Eco-Friendly Mattress
Depth (cm)
21
Number of Layers
3
Trial Period (nights)
60
Warranty (years)
5
Price Range
£219
Best Sleeping Position(s)
Back Sleeping
Stomach Sleeping
Combination Sleeping
Certifications
Assessed from Silentnight's published specification for this mattress, captured September 2026, and from regular price comparison across our UK retail partners.
Why should you choose this mattress?
If you're shopping for a child or teenager, the case here is straightforward. The Miracoil® spring system offers zoned support, which Silentnight states is scientifically proven to improve spinal alignment and posture, useful during the years when both are still developing. The EcoComfort Fibres™ layer is breathable and helps maintain a comfortable temperature, handy if your child tends to run warm at night. It's hypoallergenic and free from foam and FR chemical treatments, a genuine reassurance for parents who'd rather avoid those materials. Yes, the Medium/Firm feel may seem firm at first to a child used to something softer, but firmer support generally suits lighter bodies well. Delivery is quoted at 14 days.
Key features & layer details
Sleep surface
A luxurious quilted sleep surface sits on top, which means the first thing your child feels is a soft, cushioned finish. It adds an extra touch of comfort above the firmer layers beneath.
EcoComfort Fibres
Beneath the surface, breathable EcoComfort Fibres™ soothe and help maintain a comfortable temperature through the night. If your child is a warm sleeper, this is the layer doing the quiet work.
Support system
At the base, Miracoil® springs provide zoned support, scientifically proven by Silentnight to improve spinal alignment and posture. In practice, that means the hips and shoulders are held in a healthier position as your child grows.
Layer details from silentnight.co.uk product page, September 2026.
Best suited for?
Children
Silentnight designs this as a children's mattress, with a Medium/Firm feel and zoned Miracoil springs that give growing bodies steady, supportive comfort.
Teenagers
Zoned Miracoil springs and a Medium/Firm feel give older children steady support, and the UK Single size suits a standard teenage bed.
Warm sleepers
Breathable EcoComfort Fibres sit beneath the quilted cover and help maintain a comfortable temperature, which suits anyone who tends to run warm at night.
Allergy sufferers
The mattress is hypoallergenic and free from foam and FR chemical treatments, which gives parents reassurance if they want to avoid those materials.
Lighter sleepers
Firmer support generally suits lighter bodies well, so the Medium/Firm feel and spring system should hold a smaller frame in a steady position.
It's only available in a UK Single, so it won't work for double beds or adult couples. Anyone wanting a soft, cradling feel may find the Medium/Firm rating a little unforgiving. And at 21cm deep, it's slimmer than some sleepers expect, less of an issue for children than adults.
Save on an earlier or ex-display model
Some retailers still sell the earlier version of this mattress, or ex-display and returned stock at a lower price. These are the sizes where it costs less than the current model's best price.
Silentnight Healthy Growth Comet Eco Comfort Miracoil Mattress
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FAQ's
How firm is the Silentnight Healthy Growth Comet mattress?
Silentnight rates it as Medium/Firm. That's a supportive feel rather than a plush one, which generally suits children and lighter sleepers well, although anyone expecting a soft, sink-in surface may find it slightly firmer than they'd like.
Does the Silentnight Healthy Growth Comet come with a trial?
Yes. Silentnight offers a 60-night trial on this mattress, so you can return it if it doesn't suit your child. It also comes with a 5-year guarantee for longer-term peace of mind.
Is the Silentnight Healthy Growth Comet good for allergies?
It's listed as hypoallergenic, and it's free from foam and FR chemical treatments, which many parents prefer. If allergies are a concern, those certifications make it a reassuring option, though pairing it with a washable mattress protector is still sensible.
What sizes does the Silentnight Healthy Growth Comet come in?
It's available in a UK Single only. That fits its purpose as a children's mattress, but if you need a small double or larger you'll want to look elsewhere in Silentnight's range.
How long does delivery take for the Silentnight Healthy Growth Comet?
Silentnight quotes delivery within 14 days when ordering from its own site. Timings may differ if you buy through a retailer, so check at checkout.
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