What Types of Boilers Are There?
In the United Kingdom, the boiler is the heart of the home, providing warmth and comfort during the chilly months and ensuring a steady supply of hot water throughout the year. As environmental concerns and energy costs rise, the efficiency and type of boiler installed in a home have become increasingly important considerations for homeowners. The market offers a variety of boiler types, each designed to meet the specific needs and challenges of different households.
This article will delve into the nuances of heat-only, condensing, combi, systems and back boilers, shedding light on how they function and the unique advantages and limitations of each one.
What Is a Heat-Only Boiler and How Do They Work?
The heat-only boiler (aka conventional, traditional, open vent or regular boiler) is the traditional heating method in many UK homes, particularly if they’re older or built with multiple bathrooms in mind. These boilers function by heating water that is then stored in a cylinder until needed, relying on a separate cold water tank often situated in the loft to supply the water for a steady supply of hot water to various outlets simultaneously.
Heat-Only Boiler Pros and Cons
| Pros | Cons |
| Ideal for homes with multiple bathrooms | Requires more space for tanks and cylinders |
| Can provide hot water to several taps at once | Less efficient than combi boilers |
| Compatible with older radiator systems | Can lead to heat loss from hot water cylinder |
| Easier to maintain due to its simpler mechanics | Initial installation can be complex |
| Less likely to experience drops in water pressure | Higher operating costs compared to combi boilers |
Find out more in our detailed blog ‘What Is a Heat-only Boiler and How Do They Work?’
What Is a Condensing Boiler and How Do They Work?
Condensing boilers use a secondary heat exchanger to recover and recycle heat from exhaust gases which would otherwise be lost, significantly enhancing their efficiency and minimising waste. These boilers are engineered to capture and recycle heat that would traditionally escape into the atmosphere through the flue.
Condensing Boiler Pros and Cons
| Pros | Cons |
| Energy efficiency over 90% means lower energy bills compared to other boilers | Often has a higher initial cost |
| Lower carbon emissions than other boiler types | Complex design and installation requirements mean you probably need an expert to install it |
| Compact size lets you tuck the boiler away easily | Retrofitting a condenser boiler into an existing heating system may require additional modifications or upgrades |
| More comfortable, thanks to the consistent and reliable heating |
Find out more in our detailed blog ‘What Is a Condensing Boiler and How Do They Work?’
What Is a Combi Boiler and How Do They Work?
Combi boilers represent a modern and efficient solution to home heating and hot water, combining both functions into a single compact unit. These boilers provide hot water on demand by heating water directly from the mains, eliminating the need for a separate hot water storage cylinder or cold water tank.
Combi Boiler Pros and Cons
| Pros | Cons |
| Remarkable efficiency, with a direct heating capability that reduces thermal losses from storing hot water | May provide low flow rate when running water from multiple sources simultaneously, especially in larger homes or when high demand for hot water is common |
| Compact design lets you discreetly install it in spaces like kitchen cabinets | It depends on mains pressure, so in areas with low mains pressure, you may have diminished flow rates to your shower and taps |
| Simpler and more cost-effective installation procedures with fewer essential parts required | Lack of immersion heater there is no alternative way to heat water during a breakdown |
| On-demand hot water | |
| Remarkable efficiency, with a direct heating capability that reduces thermal losses from storing hot water |
Find out more in our detailed blog ‘What Is a Combi Boiler and How Do They Work?’
What Is a System Boiler and How Do They Work?
System boilers offer a middle ground between the traditional heat-only boilers and the modern combi boilers. Like heat-only boilers, they require a hot water storage cylinder, but they do away with the need for a cold water tank by drawing water directly from the mains. This design simplifies the plumbing installation process and allows for a continuous supply of hot water to multiple outlets.
System Boiler Pros and Cons
| Pros | Cons |
| Steady hot water supply from the storage cylinder, which ensures that hot water is readily available, even in homes with multiple bathrooms | Space required for the unvented hot water cylinder means a system may be too big for many homes, even though the boiler unit itself is small |
| Higher energy efficiency, particularly from the condensing varieties that capture and recycle heat from exhaust gases | High initial cost as systems boilers have many integrated components and need a hot water cylinder |
| Simplified installation thanks to the integration of many components within a compact boiler unit | Heat loss from storing hot water in a cylinder, which is only partly diminished by high-quality insulation in modern boilers |
| Improved water pressure due to the unvented hot water cylinder |
Find out more in our detailed blog ‘What Is a System Boiler and How Do They Work?’
What Is a Back Boiler and How Do They Work?
Back boilers are a nod to past heating systems, usually installed behind the fireplace in older homes. These boilers utilise the heat generated by the fireplace to warm up water, which is then circulated throughout the home to radiators and taps. Back boilers have been supplanted by modern boiler types, which are safer, cleaner, more efficient and easier to use and maintain.
Back Boiler Pros and Cons
| Pros | Cons |
| The dual functionality of providing heating and hot water was efficient before more modern boilers were developed | Inefficient compared to modern heating systems, as a significant amount of heat generated by the fire is lost through the chimney |
| Some back boiler could operate without electricity, which was valuable during power outages or in areas with unreliable power supplies | Huge safety concerns, particularly for potential carbon monoxide poisoning |
| Hard to maintain and repair due to their location and design | |
| Big environmental impact, as they require an open fire to run | |
| Incompatible with modern heating controls and systems |
Find out more in our detailed blog ‘What Is a Back Boiler and How Do They Work?’
Summary
The variety of boilers in the UK is rich and varied, offering solutions tailored to the diverse needs of its residents, from the simplicity and reliability of heat-only boilers to the high efficiency and space-saving design of combi boilers to the balanced approach of system boilers, each type brings its own set of benefits and considerations. By gaining a deeper understanding of how these boilers operate and the advantages each type offers, homeowners are better equipped to make informed decisions that align with their household needs, preferences and environmental values. The right boiler choice will not only ensure a cosy and comfortable home but can also contribute to the broader goals of energy conservation and environmental stewardship.
Contact the Experts
Celebrating over three decades of service, MPC Energy Ltd is at the forefront of the UK's home energy upgrade sector. Our teams are committed to quality workmanship and customer satisfaction, employing best-in-class products for all installations. Our services extend across the nation with a focus on enhancing home efficiency through the Energy Company Obligation scheme and other initiatives. When you apply for funding, we’ll handle the application work and then let you know if we can install your boiler with a full or partial subsidy. Contact us in Clydebank, West Dunbartonshire for energy assessments and installations that cater to all budgets.
For more information about our services, contact us via our website or call to speak to one of our energy consultants at +44 141 951 7887.
