Combi Boilers [The Ultimate Guide]

Matt Robinson | Updated on March 26, 2021
Combi Boiler Engineer Explaining to Customer

It’s estimated that combi boilers are installed in over 50% of homes in the UK. As the winter sets in, the heating system takes a front seat being absolutely necessary to beat the shivering winters. Choosing the right boiler to match your home and central heating system is essential if you want to save money on heating bills.

Now, in this article, we shall discuss combi boilers, an ideal choice for residential buildings. Are you worried about rising heating costs? Opting for a combination boiler is the best option. It’s pretty challenging to have an understanding of the world of boilers, there are so many models, so many manufacturers, a lot of sales and installation.

What is a combi boiler?

According to statistics, about 75% of UK homes have installed combination boilers and this is amazing. Combi boilers are a very popular choice because these systems can heat water efficiently as well as offer fantastic central heating. Therefore, it supplies heat as well as hot water which is just ideal. The combination boilers are responsible for controlling the entire central heating system from a single unit and it offers a number of benefits based on energy, space, and costs. This type of boiler is very useful because you do not need any hot water cylinder separately which helps to save a lot of space. Homes that do not have much space need to think twice before installing a boiler and these days most homes have space crunch, in a situation like this nothing is better than combi ones. These systems help hot water to flow to showers and taps. Homeowners can enjoy an uninterrupted flow of hot water without any pump. These boilers are very easy to install, saving both time and money. A combination boiler is a single unit that is more advanced than traditional boilers systems. These boilers are available in different outputs and sizes and give unlimited access to warm water. These boilers are condensing, therefore, the system utilises more of the energy produced and very little amount is wasted.

How does a combi boiler work?

A boiler is a very sophisticated device that is made up of various internal components to ensure safe functioning. There is the pressure valve for regulating water pressure; there is an expansion vessel to hold the rise in pressure that would be created because of the water heating procedure. There is also a fan that helps to throw out waste gases produced while heating process.

Combination boilers are fitted with a secondary heat exchanger which heats up the water straight away from the main water supply. This ensures continuous hot water; there won’t be an issue of water running out. Combination boilers can offer hot water instantly by remaining on the standby mode continuously. Just as you turn on the hot water supply, the boiler starts working and water starts getting hot immediately. When someone turns on the tap for hot water, the signal is sent to the boiler and water starts heating from inside. There are heat exchangers that transfer most of the heat from the gas that is burning right inside the boiler and hot water flows out. Inside there are control valves functioning in various directions allowing water to flow through taps or via central heating. You won’t get water from both the channels at the same time. You have the liberty to pre-set the desired temperature and the boiler would function with the thermostat to keep your home heated.

A combi boiler is perfect for smaller homes because you don’t need to install an expansion or feed tank, there is no need for cold water storage or hot water cylinder and this keeps your loft free. These units depend on the main water pressure to supply water in your home and this is why the rate of flow decreases if multiple outlets are used at the same time. A combi boiler works differently than a traditional unit as it has a mandatory heat exchanger which helps to heat water from the cold mains supply. Hot water is supplied instantly through a single unit which is a wall-hung one.

The modern units are manufactured in such a way that they can produce water vapor condensation which aids in extracting extra heat from the fuel. This system increases the energy efficiency reducing your monthly energy bills as more heat is generated but less energy is consumed.

Advantages of a combi boiler

A boiler is basically the heart of your property and this is why you need to install the right unit. If your local plumbers suggest a combi boiler then you must be aware of the pros and cons before installing the unit. Now recently more and more homeowners are planning to replace their traditional boilers due to increased efficiency. Combi boilers would surprise you with a multitude of benefits and that would lure you towards this amazing unit. A combi unit would have a positive effect on your home d?cor, finances, and lifestyle. Now, take a look into the advantages:

  • It is so compact – You do not need any separate cylinders or tanks and this is amazing. It’s a single package, a compact one. You could have a lot of space for home decor and to walk about. These are best for properties that have limited spaces and these days most homeowners love compact items and a boiler is no exception.
  • Instant hot water – It does not store hot water but you get an instant supply of hot water and this is impressive. You get hot water whenever you demand so there is no waiting time.
  • Economical and efficient – Traditional boilers keep your energy bills high all time but combi boilers are economical, they help you to make huge savings on energy bills. Combi boilers generate condensation and this makes it more energy efficient.
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  • Clean and very safe – Combi boilers are not much prone to accumulating debris and sludge because water is generated directly from the mains. When the boiler remains clean, issues like kettling do not occur and this saves your repair costs. The water that comes out of a combi boiler is generally safe for drinking but it also depends on the water supply in your area. Water is not stored in tanks and this makes the water cleaner.
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  • Easy installation – Combi boilers are usually pre-assembled, the fittings are basically straightforward and the pipework is definitely less because there is no tank. It takes less time and cost to set up a combi boiler. These units are very easy to install, the process is also faster. These units do not need programmable controls to put the heating on and off. It’s best for homes that have a single bathroom. These boilers are available in a wide range of models and are well-sized.

Now, when it comes to noise, there is no boiler that is silent but any excessive noise indicates an issue with the central heating. It is very important to maintain and service your combi boiler. In case you choose to sell your home; you would get a higher value if you have a combi boiler installed because of the several advantages.

Disdvantages of a combi boiler

  • These boilers are not great for homes that have a poor rate of water flow or low water pressure.
  • The rate of hot water flow is reduced when you access more than one outlet at a time. It is an issue for houses that have more than two showers.
  • Combi boilers do not yet run on solar energy.

Combi boiler installation cost

In case you are investing in a new combi boiler, be ready to pay anything between 400-2000 Franks. Basically, the price range is pretty wide but a good quality one would cost anything between 900-1500 Franks. The installation expenses vary from one manufacturer to another; it needs extra work to be done.

Are you worried about the cost of a new combi boiler installation? Most of the homeowners are always thinking about it in the UK because the cost depends on several factors like boiler type, size, cost, and complexity. There are times when the installation charges get higher than the total boiler cost. It must not matter if the overall expenses are high because it’s going to be helpful in the long run. It is a must that the installations should be carried out by an expert Gas Safe registered engineer. They are the ones who know the correct procedures and carry out stringent protocol checks. This would ensure that the installation has taken place accurately and highest standards have been maintained.

The price of combi boilers vary based on brands, the more reputed it is, the higher the price. A powerful boiler is expensive therefore its best to choose a boiler based on your requirements rather than thinking of cost-cutting. Sometimes installing the same type of boiler is a cheaper option. For instance, you wish to take off the old combi boiler and install a new combi boiler then that would be a cheaper choice. In case you don’t have a combi boiler and plan to get it, spend some more on the installation so that you can benefit in the long run. At Plumbers 911, we have our own free quote online tool that is crafted for you so that you can choose the best boiler. We are more focused on offering personal recommendations and disclose the cost of installation. We have an expert team for advice and consultation. Ask us for a quote and we shall send it to you within 24 hours.

Which combi boiler do I need?

When it comes to a combi boiler, you have a number of choices because there are so many brands selling this type. There are experts here to recommend you the right boiler because it needs assessing your home and the requirements. If you have a high demand for hot water, you need to invest in a boiler that has a higher output. Now if you are thinking which combi boiler you would buy, here are some factors you must consider:

  • The size – The size of your property has a big impact on choosing the best boiler for your home. Combi boilers are best for homes that have moderate hot water demands.
  • Combi boilers have different outputs and you must take expert help to determine the kW output requirement for your property. The boiler size you must buy depends on the number of bathrooms you have.
  • The price – Price is always a major factor so always opt for the best quote and get the installation done by experts. Do not hesitate to invest because the boiler is a big investment and one for long-term.
  • Performance ? Every boiler has different boiler performance levels. If you have a small size home, opt or a unit with low performance. Same way, for larger homes, you need a boiler with high performance.

If you really can’t decide which boiler you would invest then talk to our experts as we have years of experience in installing different units. You can rely on us that we would be offering the right choice for you.

Most popular combination boilers

There are so many boiler brands but UK homes are more dependent on Worcester and Valliant brands. Worcester is a very common choice among UK homes. Worcester Bosch, a British based brand is a domestic heating company that manufactures water heating products. Again Vaillant is also a very reputed brand that has been manufacturing finest heating products for more than 35years and is the leader in manufacturing combi boilers. Both these brands sell high-quality boilers that are manufactured keeping the environmental factors in mind. The Greenstar i is a very popular model from Worcester that comes with a 5 years warranty and the output is about 25/30 kW. The ecoTEC Plus is another great model from Vaillant that comes with a standard warranty of 2 years and is extended to 7 years if you get the installation by a Vaillant accredited installer. Both the brands sell boilers that are A-rated for efficiency and have a strong warranty.

Final words

Once you switch to a combi boiler, you immediately start reaping the advantages. We offer the boilers from the best brands and also an affordable installation service. When are you getting yours?

Talk to our team for help and advice or to book

Call 020 3880 5666