How Efficient Is My Boiler?

According to a report by the European Commission, inefficient boilers are responsible for approximately 10% of all carbon dioxide emissions in the UK. This is a significant amount, and it is important for us all to take steps to improve boiler efficiency in order to help reduce our environmental impact.

What Causes Boilers to be inefficient:

The boiler may not have been installed correctly or may not have been commissioned properly. This can result in poor performance and lower than expected efficiency levels.

The boiler may not be suitable for the property in which it has been installed. For example, if the property has very old or inefficient piping and radiator systems, then a new boiler is unlikely to make much difference. In these cases, it may be more cost-effective to carry out improvements to the existing system instead of installing a new boiler.
Boilers typically have a “set point” at which they will operate most efficiently. However, if the settings on the boiler are not correct, then it will not reach its full potential. Often, boilers are turned down too low by householders in an attempt to save money on their energy bills without realising that this could be making their boiler less efficient.

As well as these factors, there are also a number of other reasons why your new boiler may not be performing as well as you’d hoped:
It could simply be that your boiler needs some time to ‘bed in’ and reach its full potential – so don’t panic if it doesn’t seem quite right at first. Give it a few weeks and see how it goes. Your home may need some basic energy efficiency improvements before you can reap the full benefits of having a new and more efficient boiler.

As an example, properly installed insulation works wonders for keeping the heat in (and therefore costs down), while draught-proofing helps to prevent heat from escaping through gaps around doors and windows.
Heat can also escape through roofs and walls. Taking some simple steps can make quite a big difference when combined with a new boiler – so it’s definitely worth considering them beforehand or when it is installed.

How efficient is my boiler?

Efficiency is determined by many factors, including the age and model of your boiler, the quality of installation, how well it’s been maintained, and whether it’s a condensing or non-condensing boiler. A boiler which is 15 years old is likely to be around 55% efficient, while the most efficient boilers on the market now achieve around 97% efficiency.

If you have an old G-rated or even F-rated boiler, then you could save hundreds of pounds a year by installing a brand new A-rated condensing boiler. If your current boiler is B-rated or C-rated, then upgrading to a new A-rated condensing boiler could still cut your energy bills by as much as £200 a year.

The energy-saving trust estimates that replacing an old G-rated boiler with an A-rated condensing combi could save you £340 per year if you have gas central heating and are an average-sized 3-bedroom house. They also estimate that replacing your old F and E-rated boilers with an A-rated condensing system will save you between £310 and £330 per year if you have gas central heating and 1 bedroom, or between £480 and £500 if you have oil central heating. These savings will vary depending on how old your home is, and how well insulated and draft-proofed it is.

Domestic boiler efficiency rating

A domestic boiler efficiency rating is measured by dividing the total energy output of a boiler by the total energy input given to the boiler, multiplied by a hundred. (Energy output)/(Energy input) X 100.
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It is expressed as a percentage and is calculated by dividing the amount of energy your boiler uses to heat your home by the amount of energy it takes to produce the same amount of heat.

For example, if your boiler has a rating of 90%, that means it’s 90% efficient. That means for every £1 you spend on heating your home, only 10p goes to waste.

Several factors can influence boiler energy efficiency, including fuel type, operating conditions, and maintenance. Improving boiler energy efficiency can be achieved through proper equipment selection, operation, and maintenance practices.

Why are new boilers so much more efficient?

The vast majority of new boilers in the UK are now condensing boilers. Condensing boiler technology is now over 90% efficient. This means that for every £1 you spend on heating your home, 90 pence heats your home and only 10p is wasted. As much as 60% of the heat produced is wasted in a standard (non-condensing) boiler. By installing a new condensing boiler, you could decrease your energy bills by up to 40%.

Which Boilers are the most efficient?

To answer this, we need to understand a few things about boiler efficiency. All boilers have what’s called a “nominal output.” This is the amount of heat they produce when they’re operating at peak efficiency.
However, in the real world, boilers rarely operate at their peak efficiency. Their output will vary depending on the demand for heat, for example, a boiler will work harder and use more fuel when it’s cold outside and you have your heating on full blast than it will on a mild summer day when you only need hot water for showers.

This means that the nominal output of a boiler doesn’t tell us much about its real-world efficiency. To measure this, we need to look at something called the “annual fuel utilisation efficiency” (AFUE). The AFUE is a measure of how much of the fuel that goes into a boiler is actually turned into useful heat over the course of a year. Most modern boilers have an AFUE of around 90%, which means that around 90% of the fuel they consume is used to generate heat, with the other 10% lost through things like heat escaping up the flue or being released into the environment through the jacket surrounding the boiler itself.

So, if you’re wondering whether your old boiler is efficient or not, AFUE is really the most effective way to tell. And as far as new boilers go, A-rated models tend to be some of the most efficient on the market with an average AFUE of 90-93%. This means that installing a new A-rated boiler could potentially save you money on your heating bills each year compared to the typical G-rated model from 10 years ago (which would have an AFUEOF70-75%). Of course, there are lots of other factors that affect how much energy you use and how much it costs – such as thermostat settings and insulation levels – but upgrading to a more efficient boiler should help reduce your bills significantly.

Condensing boilers represent a significant improvement in both efficiency and environmental performance compared to conventional boilers. Thanks to their improved design, they are able to extract more heat from combustion gases while also emitting fewer pollutants into the atmosphere.

In Summary:

Household bills are often dominated by the expense of heating your home, particularly during the winter. During the colder months, heating costs can account for up to 60% of your monthly expenses. Due to the high cost of keeping warm in the winter, it is no surprise that the most effective way to reduce your household bills is to reduce your heating costs.

BPS offer a professional and qualified heating and boiler service. We can come out to your home or business and our engineers will assess the efficiency of your boiler and offer you any recommendations to improve it. It doesn’t always mean a replacement boiler, it could be your boiler needs a service, a repair or your pipework and radiators need flushing.
We offer an honest and trusted service in Wales, the South West through to Shropshire and the Midlands, and customer service is at the heart of what we do. Contact us today on 029 20 484114 to find out more.