Combi boilers are the next-gen boilers, fast, efficient and comfortable. Having a plate heat exchanger these heat up the water in real-time. It attracted such popularity and demand due to its smaller tank heating unwashed and reserved water. That’s what a plate heat exchanger is capable of.
Having all those complex parts like the dabble pressure switch 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 combi boilers to get yourself the best combi boiler.
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Best Combi Boiler
As combi boilers are gaining much popularity in recent times there are more than a hundred products available in the market. But not all of them are reliable enough to spend your money on it. But among these different products choosing a single one that’s best suited for your home and meeting your requirements fully is a very difficult job.
So, to save you the time and difficulties of going through all these different products to choose your boiler we have sorted out a list of some of the best tier combi boilers till now. All you have to do is match your requirements for these products and choose the one that’s most compatible with your want.
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 to 199000 BTU. Moreover, it has a maximum gas input capacity of 120000 BTU for space 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 a long period. Its internal components are made of high-quality stainless steel that helps them run for a long time. One of its best features is that it has an energy 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 cold climates and has a feature that prevents scalds. Besides, the installation process of the boiler is easy. Besides, it takes the least amount of space for installation. You can easily put it into any cabinets.
Pitfalls
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 with an efficiency rate of 94.3 % with a maximum operating pressure of 2.07bar. Finding such a good figure for efficiency is not much common among 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.
Pitfalls
This BOSCH boiler is bigger and heavier than most other combi boilers in the market. If you are planning not to move the boiler around then it might be alright for you. But if you have a small installation space for the boiler and just plan to keep it in a small cabinet then you need to think 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 up much 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 most other 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 option for your home because of its high-performance and on top of that, you can get it at an affordable price.
Pitfalls
M060SN comes with 60,000 BTU only. Though the size of the boiler is much compact and that definitely has affected the heating, yet the 60K 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 the high-pressure digital shower. The product is compatible with high pressure and bath fill only. The installation of it is very easy and quick. Also because of its small size, it doesn’t take up much space for installation.
The product has thermostatic temperature control which works perfectly to keep the bathwater at a comfortable temperature. Plus it’s very user-friendly. The LED indicator lights will show you when the water has reached your desired temperature. Moreover, the buttons and controllers make it very easy for the controllers to use it with ease.
The internal components such as the filters and check valves are always available and changeable. So if any of them are damaged you can just change them with a new one instead of throwing out the entire thing and use it for a long period. Also, the product includes two additional components – Controllers and Valve.
Mira showers have gained much popularity and reliance among the users because of its intelligent and distinct features, and user-friendly functions. To make your shower more enjoyable there are very few products that can match its high performance. So you grab one of these without any worries and enjoy your comfortable shower fully.
Pitfalls
As Fittings are not included in the product, customers have to 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 remain incomplete if you don’t consider the NTI-FTV150C as a contender. This top-quality combi boiler is a type of fire tube condensing boiler.
The combi boiler comes with a pump, a plate heat exchanger and a pressure bypass. It saves your money for buying a circulator as the pump gives you the privilege of circulation for zone valve considering the heating systems.
The product imposes excellent durability and can last a long period without breaking down frequently. The FTV heat exchanger made of high quality 439 stainless steel assures they are durable enough to run for a long time. It ensures maximum efficiency which is much more than most of the combi boilers in the market.
Also, the fire tube heat exchanger and the DHW heat exchanger show exceptional efficiency. They ensure the maximum amount of water delivery of your home with a flow rate of 3.6 GPM. Moreover, the boiler includes a high-quality outdoor reset sensor which is field-tested. So without any doubt, the NTI-FTV150C is reliable enough to spend your money on it.
Pitfalls
The fact that might bother you is that the pipes that are connected with the boiler is made of cheap plastic that might not serve you with the ultimate satisfaction, so be careful when you are joining or removing any pipe from the joint.
6. Rinnai i150SN Condensing Gas Boiler
Aspects of interest
This high-quality natural gas condensing combi boiler is definitely a good choice of combi boilers of recent times. This Rinnai i150SN is a heat-only model that ensures the comforts of your home by running efficiently.
The boiler has a heat exchanger made of high-quality stainless steel that cleans itself automatically associated with a second flat plate heat exchanger. It comes with an input rating of 150000 BTU.
The most important and noticeable feature of this boiler is its high efficiency. It has gained the highest AFUE of 95% and also a certification of the Energy Star Most Efficient. Besides, there is an outdoor reset sensor associated with the modulating pump that makes it more desirable.
The boiler is compact and light-weighted specially designed for wall mounted installation. The installation is very easy and quick and it doesn’t take up much space for installation as well. Besides the product is very user-friendly. It has an intelligent control option that can connect the two-zone pumps to the PCB. It also includes a condensing gas boiler.
Pitfalls
It’s a bit in the higher price range. But it’s always wiser to 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 designed for ease and comfort. It comes with a rating of 120000 BTU, a flow rate of 11.1 GPM and a rate of maximum 199,900 DHW. Its innovative technology works simultaneously for heating up your home and delivering hot water for domestic use. So this Energy Star most efficient certified combi boiler is definitely a great 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 boiler make it exceptional so a lot of customers prefer it above other combi boilers.
Pitfalls
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)
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
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
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 the world for a number of reasons. Other boilers like a system and regular boilers require a storage tank to store the hot water. But the combi boiler is a unit that takes care of the central heating and delivers hot water to your taps for domestic use. This boiler doesn’t take much space as it doesn’t need any tank for 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 through almost all the products available in the market and look into what features and functions 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 our desired combi boilers.
So to minimize your struggle we created a “short-cut tunnel”: the detailed buying guide. We have carefully sorted out all the possible features that you might find useful and necessary in your combi boiler so that you can have a clearer idea of what you are looking for.
Type
Combi boilers will be the core of the heating system if you’d install one. Many tasks of the day are so strictly attached to it that a little delay in its performance often puts it in the list of criticism. And that depends on the type of source it uses. You need to figure out which one will 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 popular boilers. Here, in the US, we make the use of propane the most due to its availability and so are the combi boilers fueled with. Mineral gas is also an option but mostly hits on bucks harder.
Boilers which make the use of oil instead of gas are quite dependent on the cost of oil. You may also have to fall victim to such if you have a scarcity of gas in your locality. Yet biodiesel fuel is the solution to your situation then as they’re both beneficial to cost and cleanliness.
Electric ones are mostly claimed to be a good option in terms of energy and but aren’t the best option when the cost is concerned. They mainly depend mainly upon the heat pump it uses.
Getting a quite powerful boiler which is perfect for a big house when you are buying it for a smaller house, is a waste. On the other side, if you have a bigger house and you buy a boiler which would be best for a smaller house, it won’t be able to satisfy your needs. So you need to have a clear idea of what kind of combi boiler you need for your house to start the choosing process.
Size
Size is another initial aspect to think about before starting your hunt for one of the top-notch combi boilers for yourself. Combi boiler varies at a large size range. The size of your property plays the lead role in deciding the size of the boiler. And your personal preference adds to that.
When we say the size of a combi boiler we mean the heating and hot water capabilities of the boiler as well as the physical size of the boiler. If you have a large house that has a lot of spare space, then a large-sized and more powerful boiler will be the right one for you.
Also, you need to decide the physical size of the boiler according to space decided for the installation of the boiler in your property. Larger combi boilers are generally bigger and bulkier so they need more space for installation, and the less powerful ones are usually comparatively smaller so 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 on the manual were done taking into consideration the size of the house as well as the foundation of the home. And also the ventilating system, the thickness of the wall, etc.
Heat Flow Rate
The heat flow rate is one of the most important factors to think through before buying a combi boiler. It somewhat determines the performance rate of the boiler and how well it will serve you.
The combi boilers in the market come in a large range of variety with different sizes, specialties’, features and specifications. They also vary in terms of strength from one another and their strength determines their ability to heat up your home.
You need to know the kilowattage of a combi boiler to determine its strength. At the same time, you need to have an idea of the amount of kilowatt you need in a combi boiler to do the job perfectly. If you combine the heat all the radiators you already have, produce then you will have a rough idea about the kilowatt of combi boiler needed for your home.
The efficiency is one of the most important things you need to consider before buying a combi boiler as it will not only get your job done in the least amount of time but also save your energy bills to a significant amount. And it only means saving more money and conserving more energy.
Boilers with good efficiency do your required job with the least amount of resources but on the other hand, less efficient combi boilers will not only waste your money for repairing it constantly but also will waste more energy than it actually needs. So buying a boiler with poor efficiency simply means you are throwing your money into the water without even realizing it.
So before buying the boiler, you need to look into this matter carefully and choose a boiler that will do your job without wasting much energy and thus reduce your energy bill as well.
Reliability and Durability
Reliability determines the ability of a particular boiler to remain functional for at least a few years without needing any repairs. And durability also somewhat gives an idea of how long the boiler will serve you efficiently.
Choosing the correct brand paves a way to reliable sources. Consider stainless steel as the construction material for a good combi boiler. But note that, the type of the boiler is one of the determiners of its material. Thus comes durability.
Both reliability and durability are essential factors to consider before choosing your combi boiler. A reliable and durable combi boiler will do your job well without you worrying about it breaking down and repairing it constantly. So instead of just grabbing any random boiler from some random brands, it’s important to buy a form a reliable boiler brand to avoid wasting your hard-earned money in the name of repairs.
Cost to Performance Ratio
The cost to performance ratio is an essential determination of which product you should choose to get your work done perfectly. A lower price may seem like a good choice while choosing a product excluding performance and other factors. But when you look at the cost to performance ratio, you will get a clearer idea of which combi boiler will be the best for you according to your budget and requirements.
Quality of Internal Components
The quality of the internal plays an essential role in the efficiency of a combi boiler. So it a must considered factor before buying a product for your home. Boilers with poor quality internal parts will much more fuel than needed and manage to break down every once in a while.
You will be buying the product with a decent amount of money and obviously, you wouldn’t want to waste more money to keep repairing it because of poor internal components. So it’s very important to check the quality of the internal components of the combi boiler before buying it.
Ease of Installation
The installation process of a combi boiler is a very important part of the whole buying process and it influences a lot in terms of efficiency of the boiler. The ease of installation process helps to keep the boiler in a good state as well as helps it run swiftly.
Sometimes when the installation process is difficult it can create some problems or damage any parts of the boiler. So later when we use it, it cannot run properly or effectively because of the damages. It affects the whole performance of the boiler and decreases the quality of it.
So while choosing any combi boiler to buy it might be better if you have a clear idea about the installation process of it. There’s no point in buying a product if it cannot be installed properly or get damaged during the process. That will just be another way of wasting money.
Availability of Parts
The availability of the parts of a combi boiler is one of the most important things to consider before buying it. As you’ll be paying a quite decent amount of money for buying the product, you want to make sure that you can use it for a long time and the availability of the internal parts plays one of the lead roles in deciding that.
For instance, if you buy a combi boiler that has internal parts that are usually not available and somehow any of the parts somehow gets damaged, what are you going to do in that situation? You will just have to get a new boiler again. But if the parts are available then you can just change the damaged parts with a new one and it’s good as new.
Budget
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 the product. A higher price doesn’t always mean higher quality, as well as, lower quality doesn’t always mean poor quality.
But if it comes down to quality vs price then it’s always wiser to spend a little more money on some good quality products that you can use for a long time than buying some cheap poor quality ones.
FAQ
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 with different functions available in the market and it’s hard to choose one among them. 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 a number of bathrooms then Noritz CB199-DV-NG and BOSCH ZWB are great options for you. Both of them have innovative features that can meet your expectations effortlessly. Plus they are easy to install and use but a bit heavier than most other combi boilers.
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.
