7 Best Combi Boiler Reviews - Home Gear Kit (2023)

Combi boilers are the next-gen boilers, fast, efficient andcomfortable. Having a plate heat exchanger these heat up the water inreal-time. It attracted such popularity and demand due to its smaller tankheating unwashed and reserved water. That’s what a plate heat exchanger iscapable of.

Having all those complex parts like the dabble pressureswitch it’s hard to find one that’s durable and efficient at the same time.Let’s take one step at a time in figuring out the mysteries and myths of combiboilers to get yourself the best combi boiler.


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7 Best Combi Boiler Reviews - Home Gear Kit (1)

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7 Best Combi Boiler Reviews - Home Gear Kit (2)


Noritz NRCB180DV-NG Indoor Direct Combination Boiler (Standard Vent Convertible) with Built-in Pump,...

Rinnai M060SN Condensing Gas Boiler, Natural Gas (60K BTU)



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Noritz NRCB180DV-NG Indoor Direct Combination Boiler (Standard Vent Convertible) with Built-in Pump,...



(Video) High Efficiency Boiler [Installation and Explanation]

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7 Best Combi Boiler Reviews - Home Gear Kit (4)


Rinnai M060SN Condensing Gas Boiler, Natural Gas (60K BTU)


Table of Contents

Best Combi Boiler

As combi boilers are gaining much popularity in recent timesthere are more than a hundred products available in the market. But not all ofthem are reliable enough to spend your money on it. But among these differentproducts choosing a single one that’s best suited for your home and meetingyour requirements fully is a very difficult job.

So, to save you the time and difficulties of going throughall these different products to choose your boiler we have sorted out a list ofsome of the best tier combi boilers till now. All you have to do is match yourrequirements for these products and choose the one that’s most compatible withyour want.

7 Best Combi Boiler Reviews - Home Gear Kit (5)

1. Noritz Indoor Direct Combination Boiler (NRCB180DV-NG)

Aspects of interest

If you have a large family and own a large house then the Noritz Indoor Direct Combination Boiler is a great option for you. This top-quality combi boiler is specially designed for a colder climate. The combi boiler can heat up a large home and a large volume of water for domestic use efficiently.

The boiler has a gas input capability range from 18000 to199000 BTU. Moreover, it has a maximum gas input capacity of 120000 BTU forspace heating with a turndown ratio of 11:1. The maximum flow rate is 9.2 GPM.

The boiler is durable enough to serve you efficiently for along period. Its internal components are made of high-quality stainless steelthat helps them run for a long time. One of its best features is that it has anenergy factor of 0.95 which means it can perform with an efficiency rate of 95%which is much higher than most other combi boilers.

The boiler can heat the water up to 140 degrees even in coldclimates and has a feature that prevents scalds. Besides, the installationprocess of the boiler is easy. Besides, it takes the least amount of space forinstallation. You can easily put it into any cabinets.


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Despite having so many great features it has some downfalls. The boiler is heavy and the water pressure and flow rate are low. Make sure that both of these attributes fit your needs before purchasing.

2. BOSCH ZWB Direct Vent Natural Gas Boiler

No products found.

Aspects of interest

BOSCH GREENSTAR combi boiler has gained the customers’reliance because of its great performance. The boiler can run efficiently withan efficiency rate of 94.3 % with a maximum operating pressure of2.07bar.Finding such a good figure for efficiency is not much commonamong the boilers of this size.

The boiler can heat water up to 90C and with a maximum gas supply pressure of 10.5 inches w.c. and a minimum value of 3.5 inches w.c. It has a ¾ inches gas connection and a flue size of 2-3 inches in diameter. Here, the supply water connection is 1 inch. Besides, the input BTU is 151600 whereas the output BTU is 134400 with a maximum relief capacity of 151.6 pounds/HR.

The best of the advantages of the product is that the installation process is more affordable than other combi boilers. Besides, the internal components are made of high-quality material so the boiler runs swiftly even in very cold temperatures without breaking down.


This BOSCH boiler is bigger and heavier than most othercombi boilers in the market. If you are planning not to move the boiler aroundthen it might be alright for you. But if you have a small installation spacefor the boiler and just plan to keep it in a small cabinet then you need tothink twice.

3. Rinnai M060SN Q-Series Condensing Boiler, M060SN-Natural Gas

Aspects of interest

Rinnai M060SN is a renowned combi boiler for homes and medium-sized offices. The users are satisfied with its distinct features and high performance making it a reliable product around the world. It is a natural gas condensing combi boiler that can heat up space and deliver hot water for domestic use for a home with a maximum of three bathrooms.

This compact, light-weighted combi boiler doesn’t take upmuch space for installation and the installation process is quite easy as well.It’s specially designed for wall mounting so it consumes less space than mostother combi boilers in the market.

The internal components of the boiler are made of durable materials to help it run for a longer period. Its heat exchangers are made of high-quality stainless steel and the plate heat exchanger made of copper-nickel gives the product high durability with a high-performance rate. The product also includes pipe systems made of PVC, CPVC, stainless steel, and polypropylene.

This top-quality combi boiler is definitely a great optionfor your home because of its high-performance and on top of that, you can getit at an affordable price.


M060SN comes with 60,000 BTU only. Though the size of theboiler is much compact and that definitely has affected the heating, yet the60K BTU is still a small value for bulky hot water supply.

4. Mira Showers Chrome Mode Digital Bath Fill without Fittings

Aspects of interest

Mira Showers is a digital bath fill designed for thehigh-pressure digital shower. The product is compatible with high pressure andbath fill only. The installation of it is very easy and quick. Also because ofits small size, it doesn’t take up much space for installation.

The product has thermostatic temperature control which worksperfectly to keep the bathwater at a comfortable temperature. Plus it’s veryuser-friendly. The LED indicator lights will show you when the water hasreached your desired temperature. Moreover, the buttons and controllers make itvery easy for the controllers to use it with ease.

The internal components such as the filters and check valvesare always available and changeable. So if any of them are damaged you can justchange them with a new one instead of throwing out the entire thing and use itfor a long period. Also, the product includes two additional components –Controllers and Valve.

Mira showers have gained much popularity and reliance amongthe users because of its intelligent and distinct features, and user-friendlyfunctions. To make your shower more enjoyable there are very few products thatcan match its high performance. So you grab one of these without any worriesand enjoy your comfortable shower fully.


As Fittings are not included in the product, customers haveto buy the fittings individually.

5. NTI-FTV150C Fire-Tube Condensing Combi Boiler

No products found.

Aspects of interest

Your hunt for a combi boiler in the market will remainincomplete if you don’t consider the NTI-FTV150C as a contender. Thistop-quality combi boiler is a type of fire tube condensing boiler.

The combi boiler comes with a pump, a plate heat exchangerand a pressure bypass. It saves your money for buying a circulator as the pumpgives you the privilege of circulation for zone valve considering the heatingsystems.

The product imposes excellent durability and can last a longperiod without breaking down frequently. The FTV heat exchanger made of highquality 439 stainless steel assures they are durable enough to run for a longtime. It ensures maximum efficiency which is much more than most of the combiboilers in the market.

Also, the fire tube heat exchanger and the DHW heatexchanger show exceptional efficiency. They ensure the maximum amount of waterdelivery of your home with a flow rate of 3.6 GPM. Moreover, the boilerincludes a high-quality outdoor reset sensor which is field-tested. So withoutany doubt, the NTI-FTV150C is reliable enough to spend your money on it.


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The fact that might bother you is that the pipes that areconnected with the boiler is made of cheap plastic that might not serve youwith the ultimate satisfaction, so be careful when you are joining or removingany pipe from the joint.

6. Rinnai i150SN Condensing Gas Boiler

Aspects of interest

This high-quality natural gas condensing combi boiler isdefinitely a good choice of combi boilers of recent times. This Rinnai i150SNis a heat-only model that ensures the comforts of your home by runningefficiently.

The boiler has a heat exchanger made of high-qualitystainless steel that cleans itself automatically associated with a second flatplate heat exchanger. It comes with an input rating of 150000 BTU.

The most important and noticeable feature of this boiler isits high efficiency. It has gained the highest AFUE of 95% and also acertification of the Energy Star Most Efficient. Besides, there is an outdoorreset sensor associated with the modulating pump that makes it more desirable.

The boiler is compact and light-weighted specially designedfor wall mounted installation. The installation is very easy and quick and itdoesn’t take up much space for installation as well. Besides the product isvery user-friendly. It has an intelligent control option that can connect thetwo-zone pumps to the PCB. It also includes a condensing gas boiler.


It’s a bit in the higher price range. But it’s always wiserto spend money on a good item than buying a cheap one with poor quality.

7. Noritz NRCB199DV-LP Indoor Direct Combination Boiler (Standard Vent Convertible) with Built-in Pump, Space Heating-Propane

Aspects of interest

Noritz NRCB199DV-LP is one of the best combi boiler designedfor ease and comfort. It comes with a rating of 120000 BTU, a flow rate of 11.1GPM and a rate of maximum 199,900 DHW. Its innovative technology workssimultaneously for heating up your home and delivering hot water for domesticuse. So this Energy Star most efficient certified combi boiler is definitely agreat choice.

The compact size of the boiler makes the installation procedure much easier. Also, the installation is easy and quick with the help of a wall bracket and quite cost-effective as well. Besides, the heat exchangers are made of high quality self-cleaning durable material saving you the worry and effort to clean them frequently. The product includes a propane tankless water heater.

The distinct features and functions of this combi boilermake it exceptional so a lot of customers prefer it above other combi boilers.


Despite a lot of great features, the screen of the boiler is not that much good enough as it becomes hard to read the digits, especially at low light.

3 extra combi boilers worth considering

You might find that the best combi boilers are increasingly out of stock – or discontinued by famous brands like Rinnai. Most people choose Rinnai or Noritz combi boilers because of these brands’ high-efficiency solutions, on-demand technologies, and multiple zoning options as discussed in the products above. Rinnai, for example, specializes in Energy-Star-rated condenser boiler technologies and is known for its leading 95% AFUE efficiency ratings. The different boiler versions are built to support various residential applications like single-family demands or multifamily units. They come with relevant residential and commercial warranties on parts and labor. Considering all these competitive benefits, it can be difficult to find good online buying options. Luckily, here are 3 additional combi boilers that are still available online and will hopefully stay on the radar for longer.

Rinnai M120CN Condensing Gas Boiler, Natural Gas (120K BTU)

7 Best Combi Boiler Reviews - Home Gear Kit (11)

Rinnai’s M120CN combi boiler works on natural gas and is available for indoor installation. It has a turndown ratio of 5.1:1/1.6:1. You can heat up your entire home and use hot water in showers and faucets efficiently. The combi boiler includes a stainless-steel heat exchanger, a modulating ceramic burner, and also a domestic hot water plate heat exchanger. Using smart integrations, the boiler enables multizone control for advanced space and water heating.

Rinnai M120CN allows two-zone pumps to connect to your whole-house heating and domestic hot water heating systems for up to 3 bathrooms. The compact unit has a simple user interface and can be mounted on the wall. It also offers multiple venting options and features a high AFUE of 95%, so there is no doubt about the boiler’s ideal heating and hot water capacity.

Rinnai E110C 110,000 BTU Natural Gas Condensing Boiler

7 Best Combi Boiler Reviews - Home Gear Kit (12)

This is one version of Rinnai’s E series of combi boilers. The E110C checks some major boxes for federal tax credit qualification, whole-house heating, hot water supply, and space-saving installation. It has a heating gas rate input of 26,000-110,000 BTU and a direct hot water gas rate input of 26,000-130,000 BTU. The combi boiler offers a maximum flow rate of 4.8 GPM and is wall-mountable. Rinnai’s E series is ideal for small homes with limited space heating and hot water requirements, and all of its boilers are built to deliver high efficiencies.

Noritz Nrcb180dv-Ng 9.8 GPM 180000 BTU 95% Afue Direct Vent Natural Gas Combination Boiler

7 Best Combi Boiler Reviews - Home Gear Kit (13)

This model of Noritz combi boilers uses natural gas and has a direct vent function. The wall-mountable and compact unit heats up space and water within the desired temperature ranges. Its 304 stainless steel heat exchangers ensure better resistance to corrosion and keep the boiler functional for long-term use. All the required mounting hardware, sensor, and heating pressure relief valve are available with this combi boiler. The unit’s simultaneous heating feature is a huge benefit. It allows your room to remain heated while you use hot water from a shower/faucet, so one function does not compromise the other. Noritz Nrcb180dv-Ng is the best combi boiler also because of its ultra-low emissions – only 14 ppm of nitrogen-oxide emissions. You should call in a professional to install this unit so that all local codes are considered carefully.

How Does a Combi Boiler Work

Combi boilers are the most commonly used boilers around theworld for a number of reasons. Other boilers like a system and regular boilersrequire a storage tank to store the hot water. But the combi boiler is a unitthat takes care of the central heating and delivers hot water to your taps fordomestic use. This boiler doesn’t take much space as it doesn’t need any tankfor storage. It also makes the installation a lot easier.

A Combi boiler gives you the comfort of hot water on demand. It heats the water directly from the mainline or points so it doesn’t need any storage tank. Then the hot water is delivered all around the house with the internal pipe system. And the central heating system that heats the water also heats up space simultaneously.

On the Quest to Find the Best Combi Boiler

To find one of the top combi boilers you need to go throughalmost all the products available in the market and look into what features andfunctions they have. But that’s a very long and difficult process. Moreover,some of us don’t even know what features and functions we might need in ourdesired combi boilers.

So to minimize your struggle we created a “short-cuttunnel”: the detailed buying guide. We have carefully sorted out all thepossible features that you might find useful and necessary in your combi boilerso that you can have a clearer idea of what you are looking for.

7 Best Combi Boiler Reviews - Home Gear Kit (14)


Combi boilers will be the core of the heating system ifyou’d install one. Many tasks of the day are so strictly attached to it that alittle delay in its performance often puts it in the list of criticism. Andthat depends on the type of source it uses. You need to figure out which onewill be the most compatible with your requirements.

Combination boilers are mainly of 3 types- electric,gas-fueled and oil-fueled. Among them, gas-fired ones are the most popularboilers. Here, in the US, we make the use of propane the most due to itsavailability and so are the combi boilers fueled with. Mineral gas is also anoption but mostly hits on bucks harder.

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Boilers which make the use of oil instead of gas are quitedependent on the cost of oil. You may also have to fall victim to such if youhave a scarcity of gas in your locality. Yet biodiesel fuel is the solution toyour situation then as they’re both beneficial to cost and cleanliness.

Electric ones are mostly claimed to be a good option interms of energy and but aren’t the best option when the cost is concerned. Theymainly depend mainly upon the heat pump it uses.

Getting a quite powerful boiler which is perfect for a bighouse when you are buying it for a smaller house, is a waste. On the otherside, if you have a bigger house and you buy a boiler which would be best for asmaller house, it won’t be able to satisfy your needs. So you need to have aclear idea of what kind of combi boiler you need for your house to start thechoosing process.


Size is another initial aspect to think about beforestarting your hunt for one of the top-notch combi boilers for yourself. Combiboiler varies at a large size range. The size of your property plays the leadrole in deciding the size of the boiler. And your personal preference adds tothat.

When we say the size of a combi boiler we mean the heatingand hot water capabilities of the boiler as well as the physical size of theboiler. If you have a large house that has a lot of spare space, then alarge-sized and more powerful boiler will be the right one for you.

Also, you need to decide the physical size of the boileraccording to space decided for the installation of the boiler in your property.Larger combi boilers are generally bigger and bulkier so they need more spacefor installation, and the less powerful ones are usually comparatively smallerso they take less space for installation.

Manual from Air Conditioning Contractors of America(ACCA)provides a manual on what size is suitable for your home. The calculations onthe manual were done taking into consideration the size of the house as well asthe foundation of the home. And also the ventilating system, the thickness ofthe wall, etc.

Heat Flow Rate

The heat flow rate is one of the most important factors tothink through before buying a combi boiler. It somewhat determines theperformance rate of the boiler and how well it will serve you.

The combi boilers in the market come in a large range ofvariety with different sizes, specialties’, features and specifications. Theyalso vary in terms of strength from one another and their strength determinestheir ability to heat up your home.

You need to know the kilowattage of a combi boiler todetermine its strength. At the same time, you need to have an idea of theamount of kilowatt you need in a combi boiler to do the job perfectly. If youcombine the heat all the radiators you already have, produce then you will havea rough idea about the kilowatt of combi boiler needed for your home.

Energy Efficiency

The efficiency is one of the most important things you needto consider before buying a combi boiler as it will not only get your job donein the least amount of time but also save your energy bills to a significantamount. And it only means saving more money and conserving more energy.

Boilers with good efficiency do your required job with theleast amount of resources but on the other hand, less efficient combi boilerswill not only waste your money for repairing it constantly but also will wastemore energy than it actually needs. So buying a boiler with poor efficiencysimply means you are throwing your money into the water without even realizingit.

So before buying the boiler, you need to lookinto this matter carefully and choose a boiler that will do your job withoutwasting much energy and thus reduce your energy bill as well.

Reliability and Durability

Reliability determines the ability of a particularboiler to remain functional for at least a few years without needing anyrepairs. And durability also somewhat gives an idea of how long the boiler willserve you efficiently.

Choosing the correct brand paves a way to reliablesources. Consider stainless steel as the construction material for a good combiboiler. But note that, the type of the boiler is one of the determiners of itsmaterial. Thus comes durability.

Both reliability and durability are essential factorsto consider before choosing your combi boiler. A reliable and durable combiboiler will do your job well without you worrying about it breaking down andrepairing it constantly. So instead of just grabbing any random boiler fromsome random brands, it’s important to buy a form a reliable boiler brand toavoid wasting your hard-earned money in the name of repairs.

Cost to Performance Ratio

The cost to performance ratio is an essential determinationof which product you should choose to get your work done perfectly. A lowerprice may seem like a good choice while choosing a product excludingperformance and other factors. But when you look at the cost to performanceratio, you will get a clearer idea of which combi boiler will be the best foryou according to your budget and requirements.

Quality of Internal Components

The quality of the internal plays an essential role in theefficiency of a combi boiler. So it a must considered factor before buying aproduct for your home. Boilers with poor quality internal parts will much morefuel than needed and manage to break down every once in a while.

You will be buying the product with a decent amount of moneyand obviously, you wouldn’t want to waste more money to keep repairing itbecause of poor internal components. So it’s very important to check thequality of the internal components of the combi boiler before buying it.

Ease of Installation

The installation process of a combi boiler is a veryimportant part of the whole buying process and it influences a lot in terms ofefficiency of the boiler. The ease of installation process helps to keep theboiler in a good state as well as helps it run swiftly.

Sometimes when the installation process is difficult it cancreate some problems or damage any parts of the boiler. So later when we useit, it cannot run properly or effectively because of the damages. It affectsthe whole performance of the boiler and decreases the quality of it.

So while choosing any combi boiler to buy it might be betterif you have a clear idea about the installation process of it. There’s no pointin buying a product if it cannot be installed properly or get damaged duringthe process. That will just be another way of wasting money.

Availability of Parts

The availability of the parts of a combi boiler is one ofthe most important things to consider before buying it. As you’ll be paying aquite decent amount of money for buying the product, you want to make sure thatyou can use it for a long time and the availability of the internal parts playsone of the lead roles in deciding that.

For instance, if you buy a combi boiler that has internalparts that are usually not available and somehow any of the parts somehow getsdamaged, what are you going to do in that situation? You will just have to geta new boiler again. But if the parts are available then you can just change thedamaged parts with a new one and it’s good as new.


Budget is a must considered factor while buying a product.But at the same time, it’s up to you how much money you want to spend on theproduct. A higher price doesn’t always mean higher quality, as well as, lowerquality doesn’t always mean poor quality.

But if it comes down to quality vs price then it’s alwayswiser to spend a little more money on some good quality products that you canuse for a long time than buying some cheap poor quality ones.


Q: What is the limit for combi boilers in general?

Ans: If a house has more than 4 bedrooms, a combi boiler will not be enough as you would need an extra compartment to keep water.

Q: Do I need any extra supplies to purchase along with my combi boiler?

Ans: No, because combi boilers have everything you need in a single unit.

Q: Can a combi boiler explode?

Ans: Yes. Generally, boilers overheat due to the failure of safety controls that maintain the gas and water supply, the temperature and the pressure. So in some cases, the boiler can set alight or even explode.

Final Words

There are so many different models of combi boilers withdifferent functions available in the market and it’s hard to choose one amongthem. Yet, one of these listed products might be the one you are looking for.

If you have a large house with a lot of spare spaces with anumber of bathrooms then Noritz CB199-DV-NG and BOSCH ZWB are great options foryou. Both of them have innovative features that can meet your expectationseffortlessly. Plus they are easy to install and use but a bit heavier than mostother combi boilers.

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Then we have the Mira Bath Fill that only works for heating up your shower. So if you don’t need a big and heavy boiler but just want to enjoy the comfort of a warm shower then this is a great choice to grab. It’s small and compact and does its job quite perfectly. If you are willing to push your budget a bit higher for some premium quality product then Rinnai i150SN is the one for you.


What is the average life of an ideal combi boiler? ›

Modern combi boilers should last up to 15 years with their high efficiency and fewer pressure issues when compared to a conventional boiler. Of course, this all depends on the quality of your chosen model and how well you look after the system.

What are the best American made boilers? ›

Table 1: Top U.S. Manufacturers of Boilers on ThomasNet
CompanyNumber of Employees
1Hurst Boiler and Welding Company, Inc.200-499
2Indeck Power Equipment Co.100-199
3Parker Boiler Co.50-99
4Sussman Electric Boilers50-99
6 more rows

What is better than a combi boiler? ›

A regular boiler will be able to deal with high water usage better than a combi boiler would and is usually better for properties with more than two bathrooms or where there is low water pressure.

Which combi boilers last the longest? ›

As with any product, certain brands and models are better made than others, and combi boilers are no exception to this. The most efficient, long-lasting boilers come (arguably) from manufacturers Viessmann, Alpha and Vaillant. Particularly reliable are the: Viessmann Vitodens 100-W 30kW.

Which boilers last the longest? ›

A high-quality combi boiler from a well-established boiler manufacturer such as Worcester Bosch, Viessman, and Ideal will last for many years longer than a cheaply made one. This means that a low-cost new boiler may not be a good investment especially when you consider installation costs.

Is it still worth getting a combi boiler? ›

High Efficiency: Combi boilers are highly efficient. You can save money on your heating bills by switching from a conventional boiler to a combi boiler. More Affordable: The installation cost of a combi boiler is low as compared to a traditional heating system. Combi boiler parts are easy to find as well.

Can a combi boiler be left on all the time? ›

Luckily, you can keep your boiler on all day and keep it plugged in and on standby for when you turn on your heating. However, having your heating on all day will cause your energy bills to increase exponentially.

Do combi boilers use a lot of electricity? ›

Nearly 100% energy efficient

Whilst most gas boilers have an efficiency rating of around 93%, electric combi boilers typically have a 99%–100% efficiency rating. This means you'll need fewer units of energy (kWh) to produce the same amount of heat.

Who are the top boiler makers? ›

Showing 10 out of 50 companies. Mitsui & Co Ltd, Siemens AG, Mitsubishi Heavy Industries Ltd, Siemens Energy AG, and ABB Ltd are the top 5 boiler manufacturers in the world in 2021 by revenue.

Is Weil-McLain a good boiler? ›

And of the seven brands that earned favorable ratings for predicted reliability, two of them, Weil-McLain and Williamson, were given a top mark of Excellent for owner satisfaction, which reflects how likely an owner is to recommend their brand of boiler.

Which boiler has highest efficiency? ›

Condensing gas boilers are the most cost-efficient. Gas is the cheapest fuel compared to electricity, oil, coal, and LPG. You can also switch to a low-carbon heating heat pump that reduces the cost depending on the fuel type and system you are replacing.

What is the downside of a combi boiler? ›

You can't run multiple appliances at the same time

This is because the combi boiler can only supply a certain amount of hot water at a time, whereas a conventional boiler can provide lots of water to different appliances thanks to the hot water cylinder.

How do I choose a combi boiler for my home? ›

As a rough estimate most flats, apartments and smaller houses, with up to 10, average size radiators and 1 bathroom* will require a 24 to 27kw Combi Boiler. For a medium to large 3-4 bedroom house with up to 15 average size radiators, 1 bathroom and an ensuite* bathroom, a 28-34kw Combi Boiler would be installed.

How do I choose a new combi boiler? ›

You should consider how much hot water you and your family use, the size of your property, the fuel that is available to you, your existing system and the types of boiler you can have installed. You may also want to consider other factors such as energy efficiency and options for renewable energy use.

Is it cheaper to keep combi boiler on all the time? ›

No. It is a myth that leaving your heating switched on all the time will help you save money on your energy bills, but this is not the case as your boiler will be continually heating when there is no real need.

Which combi boiler has the highest flow rate? ›

The Worcester Bosch Greenstar 8000 Lifestyle 50 is the combi boiler with the highest flow rate (20.3 litres per minute). No other boiler comes close. Even though there's daylight between the flow rate of Greenstar 8000 Lifestyle and the other combi boilers, they're still more than enough for most homes.

Do combi boilers lose pressure over time? ›

Over time a boiler can lose pressure due to leaks and boiler faults, which can lead to no hot water or central heating. It is therefore important for homeowners to diagnose when a boiler has lost pressure and how to resolve it.

Can a boiler last 30 years? ›

The answer is yes, a boiler can last for 30 years or even more, but as with any piece of equipment, its longevity is dependent on a number of factors. In this post, we will focus on high-pressure steam boilers for industrial and commercial applications and how best to extend their lives.

Can a boiler last 50 years? ›

The standard modern hot water boiler will last around 20 years, sometimes more. Older cast iron steam boilers can last longer, and may even reach 50 years—but this is rare, and you probably don't have a cast-iron steam boiler.

Can a boiler last 60 years? ›

You may have heard that boilers can last more than 50 years, but this only applies to the massive cast iron boilers of yesteryear, and even those could rarely get to half a century of operation. A more realistic estimate for the standard modern hot water boiler, probably the type in your house, is 20 years or more.

Can you drink hot water from combi boiler? ›

Drinking hot water from a combi system

Your hot water tap is fed straight from the mains with a combi boiler, just like your cold water tap. Hot water provided by a combi boiler system can therefore be used for drinking and cooking.

Can a combi boiler run 2 showers at the same time? ›

Can A Combi Boiler Run Two Showers or More? A combi boiler heats water directly from the water mains to provide instant hot water, so it's not recommended to use more than one shower at a time with a combi boiler.

Is it cheaper to turn your combi boiler off? ›

If you are going on holiday, it can be cost-effective to turn off your boiler because you will not need a hot water supply when you are away. However, it is worth noting that if you are going away during the winter months, you risk freezing your pipes if you turn off your boiler completely.

Can I turn off my combi boiler in the summer? ›

Should you turn off a combi boiler in the summer? No. Because combi boilers take care of your hot water as well as your heating needs, you'll need to leave it switched on during the summer. Even if you don't want to use your radiators, you'll still need hot water for washing dishes and bathing.

Is it OK to turn my combi boiler off at night? ›

Thankfully, turning off your combi boiler at the mains is completely risk-free. However, depending on the sort of heating system you have and how old it is, turning it off for extended periods of time may cause a problem with your central heating.

Can your pipes freeze with combi boiler? ›

If your boiler has stopped working in freezing temperatures, then there is a good chance that your condensate pipe has frozen. Luckily, this isn't a big problem and it can be easily resolved yourself without the need for an engineer.

Do I need a water tank if I have a combi boiler? ›

Combi boilers heat water directly from the mains when you turn on a tap, so you won't need a hot water storage cylinder or a cold water storage tank in the roof space. They are also very cost-effective and energy-efficient as water is heated instantly rather than being heated and then stored in a cylinder.

Can you have a power shower with combi boiler? ›

Unfortunately, power showers are incompatible with combi boilers. Power showers take their water supply from a hot water cylinder, which is an external tank only found in homes with a system or regular boiler.

Will switching to a combi boiler save me money? ›

Upgrading to a new modern combi boiler is likely to save you between 20-35% on your gas bills. If you're harbouring a relic from another time in your airing cupboard and upkeeping a boiler that's over 15 years old and likely G rated (running under 70% efficiency) then take a look at the potential annual savings below.

What is the most expensive part of a boiler? ›

Out of the components listed for a combi boiler, the most expensive ones tend to be:
  • The heat exchanger.
  • The electronic control board.
  • The diverter valve.
  • The fan.
  • The pressure relief valve.
Jan 17, 2023

What is the most important boiler appliance? ›

The safety valve is the most important safety device in a boiler or domestic hot-water system. It is designed to relieve internal pressure if a range of failures occur within the system.

Which state has the most boilers? ›

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States with the most industrial power plants/boilers
RankStateNo. Industrial Plants
1N. Carolina166
3S. Carolina91
8 more rows
Feb 29, 2012

What is the life expectancy of Weil-McLain boilers? ›

With proper maintenance, they are expected to last at least 15 years or longer. Weil-McLain boilers come with a 10 year non-prorated heat exchanger warranty for commercial boilers, 12 year non-prorated heat exchanger warranty for residential boilers and two year parts warranty for both categories.

Is Weil-McLain American made? ›

Manufacturing in Michigan City, Indiana for over 100 years, The Marley-Wylain Company, LLC through its predecessors grew to be the largest U.S manufacturer of cast-iron boilers under the Weil-McLain® brand.

Should I replace my 20 year old boiler? ›

In general, standard boilers last between 10 and 15 years in a usable state with minimum maintenance, although sometimes they might last 20 years. Beyond that, though, it's certainly worth upgrading.

What is the cheapest boiler to run? ›

Gas boilers, on the other hand, are the cheapest way to heat a house since they are more affordable to run than electric boilers.

Which type of boiler is more thermally efficient? ›

Condensing boilers offer the greatest energy efficiency if properly applied.

What is the most efficient temperature to keep the boiler at? ›

For a modern combi boiler, the radiator heating temperature should be set for a flow temperature of between 60 and 70°C. Any higher than this and the boiler won't enter condensing mode and be at its optimum efficiency and performance.

What is the future for combi boilers? ›

The new legislation on boilers that has attracted some big news headlines is that there will be no new gas boilers after 2025 - in newly built homes. So, all new homes built after 2025 will have an alternative heating system, such as heat pumps for example.

Can a combi boiler be too big for a house? ›

What happens if your boiler is too big? An oversized boiler isn't a problem for modern boilers as they're able to adjust their power output to suit the needs of the home. The exception to this is heat-only boilers.

What is the best boiler for my home? ›

Best Combi Boilers of 2023 (By Brand)
  • #1 Viessmann Combi Boilers.
  • #2 Alpha Combi Boilers.
  • #3 Vaillant Combi Boilers.
  • #4 Worcester Bosch Combi Boilers.
  • #5 Ideal Combi Boilers.
  • #6 BAXI Combi Boilers.
Mar 14, 2023

Where is the best place for a combi boiler in a house? ›

By far the most common location for combi boilers to be installed is within kitchen cupboards. With many new boilers being manufactured in compact sizes, a boiler installed in a kitchen cupboard is certainly a good idea.

What size boiler do I need for a 1200 sq ft house? ›

Boiler Capacity

An easy rule-of-thumb for BTU requirements is to figure that you need about 50 BTU per square foot of interior space in a cold climate; 35 BTU per square foot in a moderate climate; and 20 BTU per square foot in a hot climate.

Is it worth getting a new combi boiler now? ›

Replacing your current boiler is also a great opportunity to get a new heating system that is more efficient and sustainable. Your new boiler replacement will help heat your home for the next 15 years. Anticipating your future needs may be a difficult task but, with a Gas Safe engineer, you can ease the burden.

What combi boiler is best for me? ›

The top 5 best combi boilers chosen by our experts in 2023 are:
Combi Boiler RankingBoiler Make & Model
1stViessmann Vitodens 050
2ndWorcester Bosch Greenstar 4000
3rdWorcester Bosch Greenstar 2000
4thIdeal logic C30
1 more row
Mar 27, 2023

What is the greenest combi boiler? ›

A hydrogen boiler is very similar to an everyday gas combi boiler, only instead of using natural gas as fuel, it uses hydrogen gas. 100% hydrogen boilers are green since the burning of hydrogen only produces water vapour and has zero carbon output.

Why are combi boilers being phased out? ›

Why are gas boilers being phased out? Gas boilers are being phased out alongside other fossil fuel energy sources, as they release too many carbon emissions, which contribute to global warming.

Can you run 2 showers off a combi boiler? ›

Can A Combi Boiler Run Two Showers or More? A combi boiler heats water directly from the water mains to provide instant hot water, so it's not recommended to use more than one shower at a time with a combi boiler.

Is Weil McLain a good boiler? ›

And of the seven brands that earned favorable ratings for predicted reliability, two of them, Weil-McLain and Williamson, were given a top mark of Excellent for owner satisfaction, which reflects how likely an owner is to recommend their brand of boiler.

How do I choose a combi boiler? ›

As a rough estimate most flats, apartments and smaller houses, with up to 10, average size radiators and 1 bathroom* will require a 24 to 27kw Combi Boiler. For a medium to large 3-4 bedroom house with up to 15 average size radiators, 1 bathroom and an ensuite* bathroom, a 28-34kw Combi Boiler would be installed.

What type of boiler is most effective? ›

A combi boiler is generally the most cost-effective and efficient boiler around. They control both the hot water and the central heating, hence the name. These boiler types are especially popular for anyone conscious of their environmental impact and looking to reduce their carbon footprint.

What is the biggest boiler company in the world? ›

RENTECH is the leading manufacturer of water tube boilers. RENTECH manufactures industrial package water tube boilers, heat recovery steam generators (HRSG), and waste heat boilers of water tube and fire tube type.

What is the cheapest most efficient way to heat a home? ›

Natural gas is likely to prove the cheapest way to heat a home if you have this heating option available to you where you live. Although prices have risen, natural gas is the least costly form of space heating. This is followed by electricity, propane, and heating oil, from the next cheapest to the most expensive.

Are new combi boilers more efficient? ›

Upgrading to a new modern combi boiler is likely to save you between 20-35% on your gas bills. If you're harbouring a relic from another time in your airing cupboard and upkeeping a boiler that's over 15 years old and likely G rated (running under 70% efficiency) then take a look at the potential annual savings below.

What is the most economical boiler temperature? ›

What flow temperature is best? The lower you set your flow temperature the longer it will take to heat your home. It may take some trial and error to find the sweet spot for your home. Innovation charity Nesta suggests a flow temperature of 60°C, or slightly lower if your home is particularly well insulated.


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