What Is The Best Type Of Central Heating Boiler To Buy?


Do you know the differences between conventional boilers and combi boilers? Is an oil, gas, electric or LPG heating system better for your home? Purchasing a new boiler can be intimidating and expensive. Here is everything you need to know about choosing the best type of boiler and heating system to make your home energy efficient.

One of the most significant investments a homeowner can make is purchasing a new boiler. Thankfully, this is something that should only need to be done once every 15 years or so. However, you don't want to spend the next 15 years regretting the discussion you made or worse yet, suffering from it.

Whether you need a boiler for your own home, a holiday home, or a rental unit, a boiler is an investment that needs to pay for itself over time on your heating bill, and this guide will walk you through the process of finding which type of boiler you should buy.

The Main Types of Boiler

There are three main types of boilers and central heating systems, and factors relevant to your individual situation will decide which one is the best option for you.

All modern types of boiler systems are built to be energy efficient, but some are better than others.

What are Combi boilers?

Combi boilers are small compact units that can fit your kitchen cupboard, like a small hot water tank on the wall. These are the most popular and most commonly found boilers in small UK homes and apartments as there are no extra parts. These are small single hot water units that act as hot water storage cylinders and provide hot water on demand.

The advantages

The most significant advantage of combi boilers is that they are the most cost-effective boilers. In addition, combi boilers are also the most efficient boiler and typically involve the most straightforward boiler installation.

They combine and control both a home's hot water and central heating, thus the name combi boilers.

These are best fit for small homes or apartments or other purposes in which hot water demand is low.

The disadvantages

The disadvantage of combi boilers is that you need one for each bathroom or kitchen. In addition to that, combi boiler systems do not handle pressure very well, and you can only draw water from one tap at a time, meaning you cannot use the sink while the washing machine is running. Also, there is no backup tank, and combi boilers do not work well with solar power systems.

What are system boilers?

Similar to conventional boilers, system boilers are closed systems but do not require a cold water storage tank. System boilers comprise two main parts, a boiler and a cylinder.

The advantages

System boilers have a few advantages over conventional boilers. A system boiler is faster, easier to install, and has no separate cold water tank. They work well in low water pressure environments. These boilers can handle a high demand for hot water. System boilers are therefore suitable for houses with more than one bathroom.

The disadvantages

Because the system boiler comes in two parts, the home needs to have the necessary space for both the boiler and the cylinder. Also, the quality of the house's insulation can affect the performance and efficiency of a system boiler, which could impact your heating bills. In addition, the size of the hot water cylinder will dictate the amount of hot water available on demand.

What are conventional boilers?

This is the oldest type of boiler and is commonly known as a regular boiler or traditional boiler. Conventional boilers use both a hot water storage cylinder and a cold water tank.

The advantages

If the home has the necessary space available, conventional boiler systems offer some benefits that not even a combi boiler can provide. A conventional boiler is the best option for homes that have a problem with water pressure, as well as a demand for water in multiple rooms at the same time. Different sizes of hot water tanks can be fitted for different needs. This is also a good option for efficiency concerns and for use with solar power systems.

Also, while conventional boilers do not have a backup tank, most models allow for installing an electric immersion pump to act as a backup plan.

The disadvantages

One of the most significant disadvantages of a conventional boiler is that it needs time to heat up, so it cannot provide hot water on demand like a combi boiler can. Also, it does require the most space for installation as there are separate tanks for hot water and cold water, and it is typically the most expensive to install.

In addition. and especially regarding older homes and buildings, installation can be complex. Also, if the hot water cylinder is not insulated correctly, the unit's efficiency rating will suffer, resulting in higher heating bills. Check out if you should swap your conventional boiler to a combi.

Other Types of Boiler

Other types

While traditionally, boilers burn gas, several modern options allow homeowners to move away from gas and use a fuel that is either more eco-friendly or simply not so vulnerable to market conditions.

These options are not related to different types of boilers but instead refer to how combi, system, and conventional boilers can function.

What are condensing boilers?

Condensing boilers are designed explicitly with energy bills in mind. They are built for efficiency by capturing and reusing the latent heat and putting it back into the house to warm it instead of simply permitting it to escape.

Why should I use them?

A condensing boiler is the most eco-friendly option available. They maximise the heat already in your home and reuse it instead of allowing heat to escape and work to create new heat.

Condensing boilers are an investment, but if your energy bills and heating bills are the biggest concern, condensing boilers are your best choice.

What are oil boilers?

If a house is not connected to the main gas line, oil boilers may be the best option. As the name suggests, oil boilers burn oil instead of gas to make hot water and heat the house. The oil element is essentially the only thing that makes these boilers different from the others.

Why should I use them?

For isolated homes, especially in rural areas, oil boilers are typically the primary system installation. This is an entirely self-contained and insulated boiler system so it can be installed either inside or outside the home, so space, insulation, and structure do not affect the unit's efficiency.

What are electric boilers?

An electric boiler is very similar to a traditional boiler, except it runs on electricity instead of being a gas boiler.

Why should I use them?

For eco-minded people, electric boilers are the most environmentally friendly systems. They offer the quietest operation, are nearly 100% efficient, have the least amount of parts to break down and replace, can be located anywhere there is space available in the home, and have no risk of carbon monoxide leakage or creating carbon emissions.

What are gas boilers?

Like a furnace, these boilers use gas to heat water and the home. There are numerous variations of the gas boiler on the market, but they all tend to function in pretty much the same way.

Why should I use them?

Gas boilers are typically among the cheapest options. Gas is the most common and readily accessible fuel. Gas boiler systems can be used for both large or small spaces, older buildings as well as new construction.

What are LPG boilers?

Liquid petroleum gas, or LPG, boilers operate the same technology that a gas or oil system boiler uses. Known for efficiency, LPG boilers tend to be the most compact boiler system.

Why should I use them?

An LPG boiler is suitable for small spaces, environmental concerns, and LPG tends to be a cheaper fuel source than oil or gas.

Factors to Consider Before Purchasing a New Boiler


Numerous factors come into play when deciding which type of boiler system is the right heating system for your home.

So, it's best to identify what issues are the most important to you, what factors your home involves, and then see if those elements best point to installing a combi boiler, system boiler, or conventional boiler.

Learn about our in-depth comparison of central heating systems to help provide you with a deeper understanding of the different ranges of boilers.

You can use the following as a checklist to begin the process:

  • How will the costs of oil, gas, LPG, and electricity impact your heating bill?
  • Are you concerned about your carbon footprint?
  • What is your home's demand for hot water? How many rooms require hot water?
  • Do you require hot water on demand or not?
  • How stable is your home's pressure?
  • Is your home's insulation up to par?
  • What is your budget for installation and maintenance?

The answer to these questions in hand will make choosing and deciding between specific factors such as a gas combi boiler or a conventional oil boiler much easier.

In most situations, however, your home is the most significant factor in choosing a new boiler.

A combi boiler is usually the best solution for studios, 1-bedroom apartments, or for a specific bathroom.

However, as your home gets more prominent, a combi boiler will become a less efficient choice unless you are happy with installing a combi boiler in every room that requires hot water.

So, a genuine review of these questions is essential to note when deciding which boiler to purchase.

You can also head over to our other article's best heating solutions for your kitchen, what size boiler I need for my home, and also how to invest in central heating water treatment to help prepare yourself when you get to the stage of purchasing household heating systems.

Final Thoughts

A boiler is more than just a way to make hot water for your home, and it is also a heating system.

Modern boilers offer different benefits for different situations. Purchasing a new boiler is one of the most significant investments a homeowner makes. It should be done with confidence and understanding of how the other boilers address your situation.