Boilers are the beating heart of your central heating system. But all boilers are not created equal. With so many different brands and types of boiler on the market choosing the right one might seem daunting.
Fortunately, Oxbridge Plumbing and Building can advise you and guide you through all of the technical jargon so that you end up with a reliable, efficient and effective appliance which is cost effective saving you fuel money in the long term and helping the environment.
We can provide you with the following services:
New boiler installation
Boiler replacement
Existing boiler repair
Boiler servicing
Boiler Type Guide
Below is a brief guide to the different types of boilers commonly available to householders. We hope this will be useful as you take the first step towards realising your ideal heating system. However, if you have any questions please call or email our friendly and helpful engineers who will be more than happy to answer your queries.
Boiler Type 1
Name: Plain / Heat Only Boiler
What does this mean?
A Plain / Heat Only Boiler is a basic appliance that will heat the water for your radiators. It has a fuel burner that heats water as it passes through the boiler.
It does not have any ability to pump the hot water around your radiators so this must be done with a separate pump installed elsewhere in the system.
It does not heat your domestic hot water (the water for your bathroom, kitchen tap etc.). The domestic hot water has to be heated with a separate appliance such as a cylinder.
Tip: If you have a high demand for hot water, such as more than two bathrooms in use simultaneously, a Plain / Heat Only Boiler in conjunction with a cylinder is an option.
Boiler Type 2
Name: System Boiler
What does this mean?
A System Boiler will heat the water for your radiators. It has a fuel burner that heats water as it passes through the boiler.
It also has an integrated pump in the boiler cabinet that will pump the hot water around your radiators. This makes it more functional than a Plain / Heat Only Boiler.
It does not heat your domestic hot water (the water for your bathroom, kitchen tap etc.). The domestic hot water has to be heated with a separate appliance such as a cylinder.
Tip: If you have a high demand for hot water, such as more than two bathrooms in use simultaneously, a System Boiler or Plain / Heat Only Boiler in conjunction with a cylinder are good options.
Boiler Type 3
Name: Combination Boiler (usually called a Combi Boiler)
What does this mean?
A Combi Boiler will heat the water for your radiators. It has a fuel burner that heats water as it passes through the boiler.
It also has an integrated pump in the boiler cabinet that will pump the hot water around your radiators.
In addition, when you turn on a hot tap the Combi Boiler will heat your domestic hot water (the water for your bathroom, kitchen tap etc.). This means that you do not need a separate appliance, such as a cylinder, to heat your tap water.
Tip: If you have a high demand for hot water, such as more than two bathrooms in use simultaneously, a combination boiler will not provide enough hot water. In these circumstances you would need to use a Plain / Heat Only Boiler or System Boiler in conjunction with a cylinder to supply the hot water.
Boiler Type 4
Name: Combination Storage Boiler (usually called a Combi Storage)
What does this mean?
A Combi Storage Boiler will heat the water for your radiators. It has a fuel burner that heats water as it passes through the boiler.
It also has an integrated pump in the boiler cabinet that will pump the hot water around your radiators.
In addition, when you turn on a hot tap, the Combi Storage Boiler will heat your domestic hot water (the water for your bathroom, kitchen tap etc.). This means that you do not need a separate appliance, such as a cylinder, to heat your tap water.
As the name suggests, the Combi Storage Boiler also includes the ability to store hot water within the boiler. This enables it to provide an improved flow rate of domestic hot water. As an example a combi storage might deliver 20 litres per minute compared to an equivalent combi boiler delivering 17 litres per minute. However, this depends upon incoming mains water pressures.
Tip: If you have a high demand for hot water, such as more than two bathrooms in use simultaneously, a combination storage boiler will not provide enough hot water. In these circumstances you would need to use a Plain / Heat Only Boiler or System Boiler in conjunction with a cylinder to supplement the demand.
Boiler Efficiency
Above we have covered the main types of boiler but we also need to consider efficiency.
Boiler efficiency is a term which establishes a relationship between energy supplied to the boiler and energy output received from the boiler. It is written as a percentage (%).
The most efficient type of boilers are condensing boilers, such as those supplied by Worcester Bosch, achieving up to 90% efficiency.
All modern boilers are condensing boilers. If you have an old-style non-condensing boiler it will be inefficient, wasting your fuel and money. A replacement condensing boiler will save you money in the long term and make up your initial investment several times over. It will also help the environment by using less fuel and producing less exhaust gas.
Pressurised and Gravity Fed Systems
Boilers are the heart of your central heating but the systems that they are connected to can work in two different ways. They can be pressurised or gravity fed.
Older systems tend to be gravity fed. This means that they have a tank in the roof which provides the pressure for the heating system. The pressure is needed so that the heating system’s water spreads out evenly across the system filling up all of the pipework and radiators and avoiding airlocks.
New heating installations are almost always installed as pressurised systems. These do not have a header tank in the roof. Instead they consist of a sealed loop of pipework and radiators which is pressurized using the mains water supply. The mains water supply is temporarily connected to the system via a tap and pumped up to the correct pressure to ensure all of the pipes and radiators are filled with water.
All of the different types of boiler listed above are for use in pressurised systems. The only exception is the Plain / Heat Only Boiler which can also be used as part of a gravity fed system.