Your Boiler: Types, Fuels, and Key Differences

Your home’s boiler is a crucial part of your central heating system, providing warmth and hot water to you and your family. But many of us don’t know much about how boilers work.

This article aims to change that by explaining the different types of boilers, their fuel sources, and the key differences between them, with a focus on energy efficiency, environmental impact, and overall cost.

Jump to a topic using the links below:

1. The Basics: What is a Boiler?
2. Fuels: Gas, Oil and Electricity
3. Types of Boilers
4. Energy Efficiency
5. Environmental Impact
6. Upfront and Ongoing Costs

The Basics: What is a boiler?

A boiler is a device that heats water or produces steam for heating and hot water. The primary function of all boilers is to transfer heat to water. There are different types of boilers, such as gas boilers, oil boilers, and electric boilers, which work in slightly different ways but all serve the same purpose. Gas and oil boilers use a combustion process to heat water, while electric boilers use electricity

Before looking at the different types of boilers, we will explain the fuels boilers use to heat your home and hot water.

Fuels: Gas, Oil and Electricity

The fuel source a boiler uses can have a big impact on its efficiency and cost. Gas and oil boilers are usually more cost-effective than electric boilers, but they produce carbon emissions. Electric boilers are the most efficient and have the lowest carbon emissions but are the most expensive to run.

Types of boilers

There are several different types of gas boilers. Some are fueled by natural gas or propane and are connected to a gas line, while others use a spark or pilot light to ignite the burner.

The heat exchanger is a series of pipes or tubes surrounded by water, and as the gas burns, it heats the pipes or tubes, which in turn heats the water. This hot water is then pumped through pipes to radiators or other heat exchangers throughout the building.

System Boilers

System boilers, also known as sealed system or pressurized system boilers, are heating systems that use natural gas or propane to heat water, which is then stored in a hot water cylinder and used for heating and hot water.

Heat-Only Boilers

Heat-only boilers, also known as conventional or regular boilers, are heating systems that use natural gas, propane, or oil to heat water, which is then used to provide heat to a building.

They have a burner that burns the gas or oil to heat the water in a heat exchanger, and the heated water is pumped through a series of pipes to radiators or other heat exchangers located throughout the building.

Condensing Boilers

Condensing boilers are heating systems that use natural gas or propane to heat water, which is then used to provide heat and hot water to a building.

They have a burner that burns the gas to heat the water in a heat exchanger, and the cooled water is passed through a second heat exchanger made of a special type of metal designed to extract additional heat from the water.

This extra heat is used to preheat the water before it enters the main heat exchanger, increasing the system’s overall efficiency.

Combination Boilers

Combination boilers, also known as combi boilers, are heating systems that provide both heating and hot water in one compact unit. They use natural gas or propane to heat water on demand without the need for a hot water cylinder. This makes them a popular choice for small homes or homes with limited space.

Energy Efficiency

Energy efficiency is an important factor to consider when choosing a boiler, as it can significantly reduce your energy consumption and costs. Boilers are rated on a scale from A to G, with A-rated boilers being the most efficient and G-rated boilers being the least efficient. Choosing an A-rated boiler can potentially save you hundreds of dollars per year on your energy bills.

There are also other ways to improve the energy efficiency of your boiler, such as sealing and insulating your home, using a thermostat to control the temperature, and properly maintaining your boiler.

Environmental Impact

The carbon emissions produced by boilers are a significant contributor to climate change. Gas and oil boilers produce the most carbon emissions, while electric boilers have the lowest carbon emissions. If reducing your carbon footprint is a priority, choosing an electric boiler or a high-efficiency gas or oil boiler may be the best option.

Another way to reduce the environmental impact of your boiler is to use renewable energy sources, such as solar panels or wind turbines, to power it. This can significantly reduce your carbon emissions and make a positive impact on the environment.

Upfront and Ongoing Costs

The upfront cost of purchasing and installing a boiler is an important factor to consider, as is the long-term cost of operating the boiler. Gas and oil boilers are typically more cost-effective than electric boilers, but the ongoing fuel costs can vary depending on the price of gas or oil in your area. Electric boilers are more expensive to run but have lower upfront costs.

In conclusion, there are many factors to consider when choosing a boiler, including fuel source, energy efficiency, environmental impact, and upfront and ongoing costs. Understanding these factors can help you make an informed decision about the best boiler for your home.

About the author

Trades Team are experts in Heating, Plumbing and Gas Services. We provide expert Boiler Repair and Boiler Servicing to homes and businesses across the Southeast.