EcoSmart Fire
EcoSmart Fire Flex 18SS Fireplace Insert
EcoSmart Fire Flex 18SS Fireplace Insert
In stock
Smallest and narrowest Flex Single Sided size
Free UK Delivery
- 5,800 BTU/h AB3 Ethanol Burner
🚚 Estimated Delivery Date:
Delivery date to be confirmed via email once order is placed
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Buying with confidence
- Manufacturer warranty: 2 years on the bioethanol burner and stainless steel parts, 1 year on everything else.
- 45 day returns. Unused and in its original packaging.
- Damaged on arrival? Check it before you sign, and tell us as soon as you can, ideally within 48 hours, so we can sort a replacement quickly. This does not affect your statutory rights.
- Free UK mainland delivery.
- Not sure it is the right one? Call, email or chat with us before you order.
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Overview:
- The Flex 18SS is the smallest and narrowest single-sided fireplace insert in EcoSmart's Flex Series, a 578mm-wide opening built for a narrow chimney breast, stairwell wall or tight architectural niche where the wider Flex sizes wouldn't fit. It runs on the smallest burner in the Flex range and is rated for both indoor and outdoor installation.
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Design & Build:
- Mild steel surround (zinc-sealed, high-temperature powder coat) in black, framing a single pane of toughened glass around the flame. The Grade 304 stainless steel AB3 burner delivers 5,800 BTU/h (6.1 MJ/h) from a 2.5-litre tank. The burner is available in Stainless Steel as standard, or a Black ceramic-coated finish for a flat, monochrome look, at a fixed premium.
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What it does well:
- Runs 8 to 11 hours on one fill and, at 807mm tall and only 365mm deep, fits into a genuinely narrow wall recess the larger Flex sizes cannot. Rated Indoor or Outdoor, so the same unit works in a covered garden room as it does a lounge chimney breast.
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Trade-off worth knowing:
- At 40m³ it's rated for the smallest room of any size in the Flex range, and the 578mm opening won't read as a wide architectural feature the way the 42SS or 50SS does. If a wider flame picture matters more than fitting a narrow wall, the 42SS steps up considerably for a moderate price increase.
Flex 18SS questions, answered
Does the Flex 18SS need a chimney or flue?
No. It runs on bioethanol, which burns clean with no smoke, embers or soot, so there is nothing to vent. It frames into a wall or opening with zero clearance to combustibles - no masonry chimney, gas line or flue required.
Can the Flex 18SS be used both indoors and outdoors?
Yes, it is rated for both. Indoors it needs a room of at least 40m³.
How is the Flex 18SS installed?
It frames directly into a stud wall (wood or metal) or an existing hearth opening, with zero clearance to combustibles required around the frame. There is no gas line, flue or masonry work: once the opening is framed to size, the unit drops in and connects to nothing else. At 25.7kg it is a two to four-person lift into place depending on the model; check the exact figure on this page before planning your install.
What does the Flex 18SS actually cost to run for an evening?
A full 2.5 litre fill burns for 8-11 hours. We sell e-NRG bioethanol at £65 for a 20 litre carton, so a full fill is about £8 and a three-hour evening works out at roughly £2 to £3. There is no standing cost, since it only uses fuel while it is alight.
Which Flex size should I choose?
The Flex range runs from the 578mm 18SS up to the 4230mm 158SS across 12 sizes. The 18SS is the narrowest and only size on the small AB3 burner, built for a genuinely tight wall recess, stairwell or niche the wider XL-burner sizes cannot fit. If a wider flame picture matters more, the 32SS steps up considerably for a moderate price increase.
Which fuel does the Flex 18SS burn, and do you sell it?
It runs on e-NRG bioethanol, which we stock in 20 litre cartons. Bioethanol produces no smoke, embers or ash, so there is nothing to clean out after use.
Are there any accessories that fit the Flex 18SS?
Yes. Its AB3 burner takes the AB3 Lid and Black Glass Charcoal, sold separately.
Is the Flex 18SS certified for indoor use?
Yes. This model is certified to EN 16647, the UK and EU safety standard for indoor bioethanol fireplaces.
Who the Flex 18SS is for
It is a good fit if:
- You have a genuinely narrow wall recess, stairwell or architectural niche the wider Flex sizes cannot fit.
- You want the entry point into the Flex range: the smallest, lightest and most affordable size.
Consider something else if:
- You want a wider flame picture: the Flex 32SS steps up to the XL burner family and nearly doubles the fuel tank for a moderate price increase.
| Model | Burner | Pick it for | Opening width | Price | Weight |
|---|---|---|---|---|---|
| Flex 18SS (this one) | AB3 | Narrowest, fits a tight wall recess or stairwell | 578mm | £1,495 to £1,795 | 25.7kg |
| Flex 32SS | XL500 | First step up to the XL burner family, nearly double the heat | 1010mm | £2,995 to £3,445 | 45.7kg |
| Flex 42SS | XL700 | Shares its burner with the wider 60SS, no log box required | 1265mm | £3,695 to £4,145 | 60kg |
| Flex 50SS | XL900 | First size offering an integrated log-storage configuration | 1470mm | £4,095 to £4,595 | 71.4kg (All Flame) |
| Flex 60SS | XL700 | Log box standard, no All Flame option at this size | 1725mm | £4,545 to £5,095 | 83.9kg |
| Flex 68SS | XL1200 | Largest single-burner size, four configurations at one price | 1930mm | £4,795 to £5,295 | 97.1kg (All Flame) |
| Flex 78SS | XL700 | Log boxes on both sides as standard, no All Flame at this size | 2186mm | £4,795 to £5,245 | 108kg |
| Flex 86SS | twin XL900 | First size to need twin burners for full-width All Flame | 2390mm | £6,995 to £7,995 | 122kg (All Flame) |
| Flex 104SS | twin XL1200 | Even a single log box still runs twin burners | 2850mm | £7,995 to £8,995 | 146kg (All Flame) |
| Flex 122SS | triple XL900 | First size to run three burners across All Flame | 3310mm | £9,995 to £11,495 | 172kg (All Flame) |
| Flex 140SS | triple XL900 | Every configuration carries at least one log box | 3770mm | £11,395 to £12,895 | 195kg (single log box) |
| Flex 158SS | triple XL1200 | Largest and widest in the launch, two configurations only | 4230mm | £12,395 to £13,895 | 222kg (All Flame) |
Prices are current at the time of writing; follow any link for that model's live price.
Delivery Information
Delivery Information
Key Points of Interest
Key Points of Interest
Specifications
Specifications
| Category | Details |
|---|---|
| Material | Mild Steel (Zinc Sealed, High-Temp Powder Coat) Surround, Toughened Glass; Grade 304 Stainless Steel Burner |
| Weight | 25.7kg |
| Dimensions (W x D x H) | 578mm x 365mm x 807mm |
| Surround colour | Black |
| Burner finish | Stainless Steel (standard) or Black ceramic-coated (+£300) |
| Fuel | Bioethanol only (Indoor or Outdoor) |
| Thermal output | 5,800 BTU/h (6.1 MJ/h) |
| Burn time | 8-11 hours per fill |
| Fuel capacity | 2.5 litres |
| Minimum room size (indoor use) | 40m³ |
| Burner compliance | EN 16647 compliant burner (manufacturer-approved) |
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