The best condensing boilers, compared.
Top pick: Beretta Exclusive 25C condensing boiler Best value: Beretta Mynute X 25 C wall boiler – At about £1,208.84 it states combined, a wall mount, a 20 kg weight and a boiler in the box, unlike the cheaper card that splits the fuel lines. Updated 21.10.2026.
A condensing boiler recovers heat from the flue gas, so it needs a condensate drain as well as a flue. In a UK home the layout still decides comfort: a combi heats the taps from the mains with no cylinder, a system boiler uses a cylinder without loft feed tanks, and a heat-only boiler still uses header tanks. The cheaper 24 splits against methane and prints 40.4 g, so that lower price is not settled. A Gas Safe registered engineer still fits and commissions it. Checks before you order are in the [condensing boiler buying guide](/hub/hot-water/condensing-boiler/sub/condensing-boiler-buying-guide). Condensing versus combi is a false choice, because a combi, a system boiler and a heat-only boiler can all be condensing. How those layouts differ when two outlets run together is set out under [combi and system layouts](/hub/hot-water/condensing-boiler/sub/condensing-boiler-combi-vs-system).
A condensing boiler recovers heat from the flue gas, so it needs a condensate drain as well as a flue.
42 products checked · 64 hrs invested · +18,640 readers
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Personal buying guide
Question 1 of 2
How will you get hot water?
The Beretta Exclusive 25C is a steel condensing boiler at £1,226.99, measuring 27.5 × 42 × 74 cm and weighing 35 kg, with the colour cell saying Bianco and the finish bullet saying white. The box lists a boiler and a kit template, which is more than a bare boiler line, though a flue is still not named. amazon.co.uk shows 5.0 from two reviews, and the saved listing has no review text, so the stars are not a test. No fuel family, no kilowatt cell and no hot-water flow are printed. Questions about radiator use and a digital display are asked and not answered.
Pros
Cons
Best for: A reader who wants the kit-template line and will treat two stars as a sample, not a verdict
Less suitable: Anyone reading 5.0 as a UK test, or a flat that needs fuel and flow on the card
Specifications
Common questions
What do the stars say?
The listing line is 5.0 out of 5 stars from 2 reviews. The saved listing has no review text, so the stars are not a test.
What is in the box?
Boiler and a kit template. The colour cell says Bianco and the finish bullet says white. Material is steel. A flue is not named.
Is a fuel or a hot-water flow printed?
No. Questions about radiator use and a digital display are asked and not answered.
The Sime Vera HE 30 is the only card in this set that prints a hot-water flow: 13.5 litres per minute, beside 30 kW, 85 °C and 3 bar, at £980.61. The title says methane/LPG, the power-source cell says CNG/LPG, and the mount is a wall with indoor installation. A capacity cell of 5.1 litres is printed, and the card does not say that figure is a hot-water store. Included components are not listed, so a flue is not confirmed, and there is no star rating. The layout word is also missing, so 13.5 litres per minute is not labelled combi or system. The price is the appliance only.
Pros
Cons
Best for: A one-bathroom shortlist where you need a printed flow and a named fuel line before the engineer visits
Less suitable: Two outlets at once, or a buyer who needs the carton contents and a layout word on the card
Specifications
Common questions
What fuel does the listing state?
The title says methane/LPG. The power-source cell says CNG/LPG. An engineer still has to confirm mains gas or LPG.
What hot-water flow is printed?
13.5 litres per minute, with heat output 30 kW, maximum temperature 85 °C and maximum pressure 3 bar.
What does the capacity cell say?
5.1 litres. The card does not say this is a hot-water store, and included components are not listed.
The Immergas Victrix Pro is listed at £2,858.53 with a heating-only bullet, methane as the fuel, and a 30 kg weight at 49.9 × 44 × 85.1 cm. The title prints both 55 kW and 50 kW and does not say which figure to use. No hot-water flow is printed, so it is not a combi for a flat. The box lists the boiler, the siting bullet says indoor/outdoor, and the brand bullet says Immerse gas while the manufacturer cell says Immergas. There is no star rating. A heating-only output in that range is a large circuit, not a one-bathroom tap.
Pros
Cons
Best for: A heating-only replacement after the engineer has chosen which of the two kilowatt figures applies
Less suitable: A one-bathroom flat, or two showers that need stored hot water documented on the card
Specifications
Common questions
Is this a combi?
The sub-category bullet says heating only. No hot-water flow is printed, so it does not read as a combi.
Which output is printed?
The title contains both 55 kW and 50 kW. The card does not say which figure to use.
What fuel does the listing state?
Methane. A fuel question in the bullets is not answered further, so the engineer still confirms the UK gas.
The Beretta Mynute X 25 C is listed as a combined wall boiler at £1,208.84, with a 20 kg item weight and a carton of 70 × 50 × 30 cm. The box line names the boiler and nothing else, so a flue, a filter and controls are not confirmed on the card. The title says combined, the only layout word of that kind in this set, but it prints no hot-water flow and no kilowatt output. No gas family appears at all, so an engineer still has to match the appliance to mains gas or LPG before you order. The title says indoor/outdoor while the style cell says indoor installation, and those two lines cannot both be the siting instruction. There is no star rating on the saved amazon.co.uk card. Treat £1,208.84 as the appliance price, not a fitted price.
Pros
Cons
Best for: A household that already wants a combined wall boiler and will have the fuel and flue confirmed before ordering
Less suitable: Anyone who needs a printed flow, a named gas family, or one settled siting line from the card
Specifications
Common questions
Does the listing say this is a combi?
The title says combined. It does not print a hot-water flow, so the layout word is not a flow figure.
What fuel does the card state?
No gas family is printed. Country of origin is Italy. The engineer still has to match mains gas or LPG.
What is in the box?
Included components say boiler. Package dimensions are 70 × 50 × 30 cm and item weight is 20 kg.
The Immergas Victrix Superior Plus is titled at 32 kW and listed at £1,776.36, with dimensions of 44 × 25 × 78 cm and a 27 kg weight. The type bullet says methane, and a propane question is asked and not answered, so LPG is not a specification. The colour cell says Bianco and the finish bullet says white. No layout word and no hot-water flow are printed, and the box contents are not listed. The installation bullet says indoor/outdoor. There is no star rating.
Pros
Cons
Best for: A methane heating replacement where 32 kW is the figure the engineer asked you to find
Less suitable: An LPG changeover, or a household that needs a combi flow on the card
Specifications
Common questions
What fuel does the listing state?
The type bullet says methane power supply. A propane question is asked and not answered, so this is not an LPG specification.
Is the output printed?
The title says 32 kW. No hot-water flow is printed, and no layout word is printed.
What colour is printed?
The colour cell says Bianco. The finish bullet says white. Those two lines are both on the card.
The Vaillant ecoCOMPACT is a floor condensing boiler at £5,437.54, titled at 25 kW, measuring 77 × 73 × 186 cm and weighing 140 kg. It is the only card that prints an energy class, and it prints A for heat and A for water. The title says layering and the model string includes 150, without the unit litres, so this is not a stated 150 litre store. No fuel family and no hot-water flow are printed, and the box contents are not listed. A wall-mounted question is asked and not answered. There is no star rating. The footprint and the weight are a floor appliance, not a kitchen-cupboard hang.
Pros
Cons
Best for: A floor space where the engineer is replacing a stored-water boiler and will confirm the fuel
Less suitable: A wall hang in a flat cupboard, or a budget that stops near £1,000
Specifications
Common questions
Is this a wall boiler?
The title says floor. A wall-mounted question is asked and is not answered as a specification. The weight is 140 kg.
What energy class is printed?
A for heat and A for water. No other card in this set prints an energy class. That is not a measurement of the other eleven.
Does the title state a store size in litres?
The title says layering and the model string includes 150. It does not print the unit litres, so this is not a stated 150 litre store.
The Immergas Victrix 12 kW TT Plus is titled as a wall condensing boiler at £1,467.17, with 12 kW in the title, dimensions of 40 × 30 × 76 cm and a 30 kg weight. The box lists the boiler. No gas family is printed, and no hot-water flow is printed, so the card does not show whether 12 kW is the heating output for a small circuit or a combi. A bullet asks whether it needs a professional install and does not answer. There is no star rating. The wall and the kilowatt line are usable. The fuel and the layout are not.
Pros
Cons
Best for: A replacement where the engineer has already fixed the gas and the layout, and 12 kW is the figure to check
Less suitable: A first order from the listing alone, or a flat that needs a printed flow
Specifications
Common questions
Is the output printed?
The title says 12 kW. No hot-water flow is printed, and the card does not say whether that figure is for heating only or for a combi.
What fuel does the card state?
No gas family is printed. The engineer has to match the appliance to mains gas or LPG before you order.
Does the listing say it needs a professional install?
That question appears in the bullets and is not answered. Domestic gas work is still for a Gas Safe registered engineer.
The Wolf CGB-2 20 Comfortline is listed at £2,558.25 as a condensing gas boiler whose title refers to a heating circuit, with dimensions of 37.8 × 44 × 79 cm and a 40 kg weight. It prints no hot-water flow, so it does not read as a combi. The title says gas and does not say methane, LPG or CNG, and a gas-type question in the bullets is unanswered. Included components are not listed. There is no star rating. At this price the card still leaves the fuel family and the carton contents for the engineer.
Pros
Cons
Best for: A heat-only replacement once the engineer has seen the header tanks, flue and condensate
Less suitable: A flat without loft tanks, or a buyer who wants a combi flow on the card
Specifications
Common questions
What fuel does the listing state?
The title says gas. It does not say methane, LPG or CNG. A gas-type question in the bullets is not answered.
Does the title say combi?
No. It refers to a heating circuit and prints no hot-water flow.
What is in the box?
Included components are not listed. A flue, a filter and controls are not confirmed on the card.
The Immergas Victrix Exa 24 is the lowest appliance price in this set at £951.54, with a style cell that says methane 24 kW and a type bullet that says CNG powered. Those two fuel lines do not agree, and an engineer cannot treat either as the finished specification. The item-weight cell prints 40.4 g, the same figure as the package weight, and a wall boiler is not a forty-gram object. The installation bullet says indoor/outdoor, the box lists the boiler, and there is no hot-water flow and no layout word. There is no star rating. The price is low because the card is incomplete, not because the specification is settled.
Pros
Cons
Best for: A reader who will ignore the price until the fuel cells and the weight are corrected on the live page
Less suitable: Anyone using the gram weight or the lower price as a reason to order
Specifications
Common questions
What fuel does the listing state?
The type bullet says CNG powered. The style cell says methane 24 kW. Those two lines disagree, and a further gas-type question is not answered.
What weight is printed?
40.4 g, on both the item weight and the package weight cell. Treat that as a card error, not as the mass of the boiler.
Can it be used outdoors?
The installation bullet says indoor/outdoor. That question is not answered as a specification, and it is not a UK siting approval.
The Immergas Victrix Superior 32 ErP is a £2,266.30 card whose title says CNG, with dimensions of 40 × 30 × 76 cm and a 25 kg weight. The installation bullet says indoor/outdoor, and the box line lists the boiler. It does not say combined, system or heating only, and it prints no hot-water flow and no kilowatt cell, so the 32 in the name is not a stated output. CNG on an Italian-brand card is not, by itself, a finished UK mains-gas specification. There is no star rating. At this price you are still looking at an appliance-only listing with the layout left blank.
Pros
Cons
Best for: A reader who already has a fuel match for the CNG wording and only needs the appliance dimensions
Less suitable: A household choosing between a combi and stored hot water, or anyone who wants a printed flow at this price
Specifications
Common questions
What fuel does the listing state?
The title says CNG. A fuel question in the bullets is not answered with another specification. CNG is not, by itself, a finished UK mains-gas setup.
Can it be installed outdoors?
The installation bullet says indoor/outdoor. The question is not answered as a specification, and the bullet is not a UK siting approval.
Is a combi or heating-only layout printed?
No. The card does not say combined, system or heating only, and it prints no hot-water flow.
The Baxi Victoria Condens 24/24F is listed at £1,204.50, with a manufacturer cell that says Baxi, a white finish, dimensions of 28 × 40 × 70 cm and a 27 kg weight. A bullet says control by LCD screen or mobile phone, while a separate digital-display question is not answered. 24/24F is the model name, and no kilowatt cell is printed, so it is not a stated 24 kW output. No fuel family and no hot-water flow appear. A question about a small flat is asked and not answered. There is no star rating.
Pros
Cons
Best for: A reader who already has the output and fuel from the engineer and wants the control bullet on file
Less suitable: A one-bathroom shortlist that needs a printed flow, or anyone reading 24/24F as 24 kW
Specifications
Common questions
Does the card print an output in kW?
No. 24/24F is the model name. No kilowatt cell is printed, so it is not a stated 24 kW output.
What control does the bullet mention?
LCD screen or mobile phone. A separate digital-display question is not answered.
Does the listing say it suits a small flat?
That question is asked and not answered. The card also prints no fuel family and no hot-water flow.
The Immergas Victrix Zeus Superior 32 ErP is listed at £2,346.90 with CNG in the title and methane in the type bullet, so the fuel lines disagree. The weight cell prints 72.8 g. Dimensions are given as 40 × 30 × 76 cm, which is a boiler-sized carton rather than a 73 gram part. The installation bullet says indoor/outdoor. There is no combi, system or heating-only wording, no hot-water flow, and no box list. There is no star rating. The mid-set price buys a conflict on the card, not a specification you can order from.
Pros
Cons
Best for: A reader checking whether the live page has corrected the fuel lines and the gram weight
Less suitable: Anyone who needs one fuel family, a kilogram weight, or a printed layout before paying £2,346.90
Specifications
Common questions
What fuel does the listing state?
The title says CNG. The type bullet says methane power supply. Those two lines disagree.
What weight is printed?
72.8 g. Treat that as a card error. The dimensions, 40 × 30 × 76 cm, are a boiler-sized carton.
Is a layout printed?
No combi, system or heating-only wording, and no hot-water flow. Included components are not listed.
Scores read the twelve amazon.co.uk cards saved on 20 October 2026. This is not a laboratory test. Eleven cards have no star rating. The only rating is 5.0 from two reviews with no written text. Listing facts are worth 50, what the card lets you check is worth 20, price against those facts is worth 20, and reviews are worth 10. The weights sum to 100. The highest score is the top pick. Best value is the entry-band card that states a combined layout, a wall mount, a kilogram weight and a boiler in the box, on a different listing from the top pick.
Listing facts
50%A named fuel family scores higher than the word gas alone, and two fuel cells that disagree score lower. A layout word, one kilowatt figure and a printed hot-water flow add points. A weight in kilograms counts. A weight in grams does not.
What the card lets you check
20%A stated wall or floor mount, a siting line that does not conflict, a boiler named in the box, an energy class and a control bullet. The block is capped at 20. Siting cells that disagree are deducted once.
Price against those facts
20%The price block rewards a printed flow under £1,000, then an entry-band card with a layout word and a kilogram weight. It is not a prize for the cheapest title when the fuel cells disagree or the weight is in grams.
Reviews
10%No star rating scores low. Two reviews and no written text score a little higher and are still not a test. A star line is not a measurement of efficiency or flow.
Choose the layout, the fuel word and any printed flow before the price. These twelve cards are appliance listings, not fitted quotes, and a Gas Safe registered engineer still has to match the boiler to the house.
A condensing boiler recovers heat from the flue gas that an older boiler would send outside, so it needs a plastic condensate drain as well as a flue. In a UK home the layout still decides comfort. A combi heats the taps from the mains and does not use a hot-water cylinder. A system boiler heats a cylinder and does not need loft feed tanks. A heat-only boiler still uses header tanks.
A kilowatt line is not a hot-water flow, and two figures on one title are not one output. The Victrix Pro prints both 55 kW and 50 kW. The Baxi model name 24/24F is not a printed kilowatt cell. Only the Sime prints a flow, 13.5 litres per minute.
Methane or CNG on these Italian-brand cards still has to be confirmed as mains natural gas or LPG. The Exa 24 and the Zeus Superior print both words and they disagree. An unanswered propane question is not an LPG specification.
The twelve prices, about £951.54 to about £5,437.54, are the appliance only. Most cards name a boiler in the box and do not list a flue, a filter or controls. A gram weight, 40.4 g or 72.8 g, is a card error, not a reason the cheaper listing is better value.
Layout decides whether the boiler heats the taps or only the radiators. A combi suits one bathroom with decent mains pressure and does not need a cylinder. A system boiler or a heat-only boiler is the usual path when two outlets run together or a cylinder is staying. Energy Saving Trust is the plain-English source for those three layouts. In this set the Beretta Mynute X 25 C is the card titled combined, at about £1,208.84, with a 20 kg weight.
Keep the fuel word, the kilowatt figure and the hot-water flow as three separate checks. Methane, or CNG on these Italian-brand cards, has to be confirmed as mains natural gas by a Gas Safe registered engineer. The Sime Vera HE 30 title says methane/LPG and the power-source cell says CNG/LPG. The Victrix Exa 24 bullet says CNG and the style cell says methane. The Zeus Superior title says CNG and the bullet says methane.
Three typical situations, each with a recommendation from this comparison.
You need a wall boiler with a fuel line and a printed flow before the engineer visits. The Sime Vera HE 30 is the top pick here: 13.5 litres per minute, 30 kW and methane/LPG at about £980.61. It does not name combi or system, and the box list is blank.
You already want a combined wall boiler and you will have the fuel and the flue confirmed before you order. The Beretta Mynute X 25 C is best value at about £1,208.84: the title says combined, the weight is 20 kg and the box names the boiler. It prints no flow.
You are replacing a boiler that still uses header tanks, and the engineer has seen the tanks, the flue and the condensate. The Wolf CGB-2 20 title refers to a heating circuit and prints no hot-water flow. It says gas, not methane, LPG or CNG, and the box list is blank.
The top pick is the Sime Vera HE 30 at about £980.61. It scores 60, the highest in this set, because it is the only card with a printed hot-water flow of 13.5 litres per minute, beside 30 kW and a methane/LPG line. It does not name the layout, list the box or show a star rating. Best value is the Beretta Mynute X 25 C at about £1,208.84, a different listing: the entry-band card that says combined, wall, 20 kg and a boiler in the box. The cheaper Exa 24 at about £951.54 still splits CNG against methane and prints 40.4 g, so the lower price is not best value. Skip the Sime if you need two outlets at once or a box list. Skip the Mynute if you need a printed flow or one settled siting line.
Beretta Mynute X 25 C wall boiler
At about £1,208.84 it states combined, a wall mount, a 20 kg weight and a boiler in the box, unlike the cheaper card that splits the fuel lines.
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 named below. amazon.co.uk prices and star lines on these twelve listings were read on 20 October 2026. Page updated 21 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 and star lines are taken from those listings. We did not run a lab test.
