The best boiler stoves, compared.
Top pick: Prity K1 CP W8 water-jacket stove Best value: Prity S3 W17 – Highest value score at about £801.53 if the plate confirms the 17 kW water bullet. The heat-output field still says 5 kW. Updated 22.10.2026.
A boiler stove is a solid-fuel stove with a water jacket or back boiler. It heats the room it stands in and sends hot water to radiators or a cylinder. These six amazon.co.uk listings are cookers and fireplace stoves, plus the OtoSystem cooker under the same FGW15 name. The useful figure is a stated split between room output and water output. A Defra line, a CE mark or a German approval is not a UK exemption, and none of these six pages states one. The stove has to sit on a water circuit the manual allows, be notified under the Regulations, and must not be lit dry. The checks before you pay are in the [boiler stove buying guide](/hub/fireplaces-and-stoves/boiler-stove/sub/boiler-stove-buying-guide). A dry wood burner does not do that second job. That band is the appliance on the shelf. It is not a typical UK installed cost. Those are publisher or retailer figures, not quotes for these six models. The page uses the same model name, states 14 litres of water rather than 15, and does not split 15+5 kW into words.
A boiler stove is a solid-fuel stove with a water jacket or back boiler. It heats the room it stands in and sends hot water to radiators or a cylinder.
22 products checked · 64 hrs invested · +18,600 readers
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Personal buying guide
Question 1 of 2
What shape do you want?
The Prity K1 CP W8 is a 74 kg cast-iron stove at £560.00, the lowest shelf price in this set, and the listing says the water jacket feeds central heating. Across 26 amazon.co.uk ratings it sits at 3.9. Nine captured reviews come from Spain, France, Germany, Italy and Belgium, and none is headed United Kingdom. Reviewers in Spain and France say the room and several radiators get warm: one French account describes about 100 m² with five radiators, and one Spanish account a 45 m² room, about five radiators and a hot-water heater. The page never states kilowatts to the room or to the water, and it does not list boiler litres or a flue diameter, so those radiator stories are not a figure you can hand to an installer. An Italian reviewer says the cast iron cracks into filaments, and a French reviewer says the outlet water runs very hot if the fire is loaded hard. The coverage field says about 46 m², and a flue is not listed in the box.
Pros
Cons
Best for: You already have the manufacturer's output figures from somewhere other than this listing, and you want the lowest shelf price in the set.
Less suitable: You need a labelled water kilowatt before you size radiators, or a Defra exemption stated on the page.
Specifications
Common questions
Does the listing state a water output in kilowatts?
No. The page says there is an integrated water heater and does not give kilowatts to water or to the room.
Is a flue included?
The included items do not list a flue pipe or a liner.
Does the page say the stove is Defra exempt?
No. Defra exemption is not stated on this listing.
The Prity FGW15 is a 136 kg wood cooker at £888.02, and it is the only listing in this set that states the split in words: 5 kW nominal to the room and 15 kW nominal to the water, with a 15 litre boiler and 1 inch inlet and outlet. Across 51 amazon.co.uk ratings it sits at 3.8. Twenty-two texts were captured, and two are headed United Kingdom. One UK reviewer says it saves money on central heating. Marc Fowler says it heats water in about an hour, and he also says the air control is poor, wood use is high, it will not hold overnight, and it needed fuel about every 30 to 40 minutes. Other reviewers praise the oven for bread and stew, and they also report smoke when the draught is closed, steel rather than the cast iron the material field names, and a flue that is not in the box. The listing prints efficiency as 80% and as 76.4%, does not say the stove is Defra exempt, and names professional installation. In this set it is the top pick, because an installer can read a room figure and a water figure without guessing which half of 15+5 is which.
Pros
Cons
Best for: You need a cooker with a stated 15 kW to water and you will have it installed on a live water circuit.
Less suitable: You need a Defra exemption, an overnight burn, or a flue pipe in the box.
Specifications
Common questions
What outputs does this listing state?
It states 5 kW nominal space heating and 15 kW nominal water heating, with a 15 litre boiler. It also prints efficiency as 80% and as 76.4%.
What do the UK reviews say?
Two texts are headed United Kingdom. One praises central-heating savings. One says the air control is poor, wood use is high, and it needed fuel about every 30 to 40 minutes.
Is a flue included?
No. A reviewer says you need to buy the flue pipe separately, and the listing does not include one.
The Prity W12 PM is a 115 kg cooker back boiler at £799.00. The title says 4+12 kW, a bullet says a maximum of 16 kW, and the heat-output field says 12,000 watts, so the page does not give you one room figure and one water figure in words. It is rated 3.2 from 6 amazon.co.uk ratings. Four captured texts come from Spain, France and Italy, and none is headed United Kingdom. Those texts do not repeat a praise theme: reviewers say the body is steel plate with only small cast-iron parts, a French owner of an earlier example says the heating body pierced after more than ten years as main heating, and another reports scratches on arrival. An Italian reviewer returned it because the house had no system to connect it to. The flue is stated as 130 mm on top, and the box lists an instruction manual rather than a flue. BImSchV on the page is German law, and the listing does not say the stove is Defra exempt.
Pros
Cons
Best for: You want a cooker shape around £799 and an installer will read the data plate rather than the conflicting Amazon fields.
Less suitable: You need one agreed water kilowatt, a cast-iron body the reviews confirm, or a circuit you do not have yet.
Specifications
Common questions
What output does the listing actually state?
The title says 4+12 kW. A bullet says maximum thermal output 16 kW. The heat-output field says 12,000 watts. The page does not repeat a room figure and a water figure in words.
Is the body cast iron?
The material field says alloy steel. Reviewers in Spain and France say only small parts are cast iron.
Does the box include a flue?
Included components are an instruction manual. A flue is not listed.
The Prity S3 W17 is listed at £801.53 and weighs 118 kg. One bullet says 17 kW to the water jacket, 5 kW to the room and 22 kW maximum, with a 23 litre jacket, logs up to 42 cm and a 130 mm flue. The heat-output field on the same page says 5 kilowatts, and the coverage field says 5 square metres beside a bullet of 125 m². Efficiency is printed as 80% and as 75.5%. The title says multi fuel and the heating-element field says wood burning, and the ventilation field says vent free, which conflicts with the flue. The captured listing has no star line and no review text. Defra exemption is not stated. It is the best value in this set only if an installer confirms the plate, because the bullet is the only place the 17 kW water figure appears.
Pros
Cons
Best for: You want a stated water kilowatt below £888.02 and you will not order until the data plate matches the 17 kW bullet.
Less suitable: You need owner reviews, one coverage figure, or a Defra exemption printed on the listing.
Specifications
Common questions
Which kilowatt figure should you use?
The description says 17 kW to the water jacket, 5 kW to the room, and 22 kW maximum. The heat-output field says 5 kilowatts. The page does not say which figure is nominal.
What efficiency does the listing print?
It prints about 80% and 75.5%. Both figures are on the page.
Is there a customer rating?
The captured listing has no star line and no review text.
The OtoSystem FGW15 is a wood cooking stove at £850.00, 136 kg, with an oven of 395 × 410 × 190 mm and a water volume of 14 litres. The model name matches the Prity FGW15 and the overall size is the same outline, but the brand is OtoSystem and the output is printed as 15+5 kW without the words to the room and to the water. The material field says alloy steel. Efficiency is given as 80, with no second percentage on this page. The captured listing has no star line and no reviews, and the flue diameter is not stated. A cooker £38.02 below the Prity listing is not the same evidence: you still cannot quote a water kilowatt from this page.
Pros
Cons
Best for: You want a cooker with a stated oven and a stated water volume, and the installer will take kilowatts from the plate.
Less suitable: You want the Prity listing's written 5 kW and 15 kW split, or any owner reviews before you pay £850.00.
Specifications
Common questions
Is this the same stove as the Prity FGW15?
The model name is FGW15 and the size and weight match that listing. The brand is OtoSystem, the water volume is 14 litres rather than 15, and the output is not split into 5 kW and 15 kW in words.
Does it have an oven?
Yes. The listing gives oven dimensions of 395 x 410 x 190 mm.
Is there a star rating?
No rating line and no reviews were on the captured page.
The Prity W15 is a 115 kg fireplace boiler stove at £830.00, listed as made in Bulgaria by Prity 95 LTD. The title says 15+5 kW and the space-heating bullet repeats 15+5 kW without saying which number is the room and which is the water. The heat-output field says 20 kilowatts, and the coverage field says up to 308 m³. A bullet claims CE, BImSchV2 and ECO design. BImSchV2 is German law, and an Ecodesign line on a listing is not a Defra exemption, which this page does not state. The flue is 130 mm. The captured page has no star rating and no review text, and boiler litres are not given. You cannot size radiators from 15+5 until someone labels the two numbers.
Pros
Cons
Best for: You want a non-cooker boiler stove and you already have a manual that labels the 15 and the 5.
Less suitable: You are buying because the bullet says ECO design, or you need a water kilowatt written in words.
Specifications
Common questions
Is the 15+5 kW split explained?
No. The title and the space-heating bullet both say 15+5 kW. The heat-output field says 20 kilowatts. Room and water are not labelled.
Does Ecodesign on the bullet mean Defra exemption?
The bullet says ECO design. It does not say Defra exempt. Those are different checks.
Are there amazon.co.uk reviews?
The captured page has no rating line and no review text.
Six amazon.co.uk boiler-stove listings were scored on a 0–100 scale from the capture of 19 October 2026. Stated outputs and circuit facts are 35 points: room kilowatts and water kilowatts as two labelled figures, with boiler litres, flue diameter and connections. Points fall when a title such as 15+5 kW is not split, when a heat-output field disagrees, or when two efficiency percentages are printed and not explained. Review evidence is 25 points, from the star line and whether any captured text is headed United Kingdom. A rating with no UK-headed text is not treated as British owner opinion, and no star line is a heavy cut. Installer use is 25 points: whether you could brief a heating engineer from the page, including a warning that the stove must not be lit dry. Value is 15 points, the price against that brief, not the lowest shelf price. The highest score is the top pick. The best price against a usable water figure, with the plate still to be confirmed, is the best value. This is not a lab test. An Ecodesign or BImSchV line is not a Defra exemption. None of these six pages states one.
Stated outputs
35%Room kilowatts and water kilowatts as two labelled figures, plus boiler litres, flue diameter and connections. A title such as 15+5 kW that is not split, a disagreeing heat-output field, or two unexplained efficiency percentages scores lower.
Review evidence
25%The amazon.co.uk star line, the rating count, and whether any captured text is headed United Kingdom. A rating with no UK-headed text is not treated as British owner opinion. No star line is a heavy cut.
Installer use
25%Whether you could brief a heating engineer from the page: a water kilowatt, a room kilowatt, and a warning that the stove must not be lit dry.
Value
15%Shelf price in GBP against a usable water figure, not the lowest price on its own. The £560 stove is incomplete on kilowatts, so a low price does not win this score by itself.
Match the water kilowatts and the room kilowatts first, then smoke control, then the circuit the manual allows. The shelf price is the appliance only. A star line with no United Kingdom heading is not British owner opinion. None of these pages states a Defra exemption.
A boiler stove is a solid-fuel stove with a water jacket or back boiler. It heats the room it stands in and it sends hot water to radiators or a hot-water cylinder. A dry wood burner does not do that second job. The six listings in this comparison are on amazon.co.uk, captured on 19 October 2026, at shelf prices of £560.00, £799.00, £801.53, £830.00, £850.00 and £888.02. That band is the appliance on the shelf. It is not a typical UK installed cost.
A title such as 15+5 kW, or a heat-output field that disagrees with the title, is not a room figure plus a water figure. Reviewer stories about radiators getting warm are not the rated output.
Ecodesign, a CE mark or German BImSchV is not a Defra exemption. Only the Prity W15 bullet claims ECO design, and that page does not say Defra exempt. None of the six pages states an exemption.
HSE guidance is not to fire a solid-fuel back boiler or wet stove without circulating water. The flue, liner, pump, alarm and plumbing are not in the shelf price.
Use two numbers from the manufacturer: kilowatts to the room and kilowatts to the water. Do not treat a single heat-output field as the answer when the same page prints a different total. In this set only the Prity FGW15 states the split in words, 5 kW nominal space heating and 15 kW nominal water heating, with a 15 litre boiler.
Smoke control is separate from the kilowatt line. Ask the council, then check the exact model on the Defra exempt list if you will burn wood. Authorised smokeless fuel is the other legal route. None of these six listings states a Defra exemption, so this set is not a smoke-control shortlist. An Ecodesign claim, a CE mark or a citation of German BImSchV is not that exemption. Only the Prity W15 bullet says ECO design, and that remains the seller's line. The circuit has to match the manual.
Three typical situations, each with a recommendation from this comparison.
You want an oven and a water figure written in words before you pay. The Prity FGW15 is the top pick at about £888.02: 5 kW to the room, 15 kW to the water, a 15 litre boiler, and 3.8 from 51 ratings. It does not state a Defra exemption, and the flue is not in the box.
You want a stated water kilowatt below the cooker price, and you will not order until the plate matches the listing. The Prity S3 W17 is the best value at about £801.53. The bullet says 17 kW to water and 5 kW to the room. The heat-output field on the same page says 5 kW, and there is no star line.
You already have the manufacturer's output figures from somewhere other than this listing, and you want the lowest price in the set. The Prity K1 CP W8 is about £560, 74 kg, with 3.9 from 26 ratings. The page does not state room or water kilowatts, and no captured review is headed United Kingdom.
The top pick is the Prity FGW15 at about £888.02. It is the only listing in this set that states 5 kW nominal to the room and 15 kW nominal to the water, with a 15 litre boiler, and it sits at 3.8 from 51 ratings. The best value is the Prity S3 W17 at about £801.53, and only if an installer confirms the data plate: the bullet says 17 kW to water and 5 kW to the room, while the heat-output field says 5 kW. None of these six pages states a Defra exemption. A boiler stove must not be lit with the water disconnected.
Prity S3 W17
Highest value score at about £801.53 if the plate confirms the 17 kW water bullet. The heat-output field still says 5 kW.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources used for this comparison. amazon.co.uk prices, stars and review counts were taken from the listings on 19 October 2026.
This page contains affiliate links to amazon.co.uk (tag pcuk26-21). If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are from the listings. This is not a laboratory test.
