How to make your boiler more efficient

With heating bills rising and temperatures starting to drop, it’s important to get the most out of your boiler. With a few simple adjustments and checks, you can make sure you’re keeping your home warm this winter without breaking the bank.

A boiler’s efficiency describes its ability to convert energy into heat. This impacts how quickly the water in your house heats up, aswell as the efficiency of your central heating system.
To run efficiently, a boiler’s pressure should be between 1 and 1.5 bar when your central heating system is off, and between 1.5 and 2 bar when your heating is on. If your boiler’s pressure is close to 0 bar, the pressure is too low, and if it's closer to 3, it’s too high. This is often an indicator of a fault with your boiler and will likely negatively impact its efficiency.
To improve your boiler’s efficiency, you should regularly bleed your radiators, insulate your pipes and keep it at the optimal temperature depending on the time of year. In winter, this is usually between 60°C and 70°C, but in warmer months, the temperature can be lower.

How is boiler efficiency measured?

All boilers are given an efficiency rating, which indicates how well it can convert its fuel into heat for your hot water and central heating. In the UK, boilers are given two ratings to indicate their efficiency. Firstly, an Energy-related Products (ErP) rating ranks the efficiency of a boiler or other heating appliances from A-G, with all boilers sold in the UK required to be A-rated by law, which indicates high efficiency.

Boilers are also given a ‘Seasonal Efficiency of a Domestic Boiler in the UK’ (SEDBUK) rating, which uses percentages to indicate the efficiency of a boiler. If your boiler has a SEDBUK rating of 90%, this means that it is 90% efficient and only 10% of the energy is lost and not converted into heat.

Both ratings allow consumers to make informed choices regarding the efficiency of their boilers before they purchase. However, it should be noted that these ratings only apply to brand new boilers and your boiler’s efficiency will drop over time if it isn’t properly maintained.

The benefits of a more efficient boiler

There are many benefits to increasing your boiler’s efficiency and the biggest advantage you might notice is a decrease in your energy bills. With a more efficient boiler, the heat produced will be better utilised across your home. This is because less of the energy will be wasted which means you aren’t paying for energy that’s not being used. Not only will a more efficient boiler save you money on your energy bills long-term, but you’ll also save yourself the hassle of more frequent maintenance and upkeep, which can become costly.

With less heat being lost, your home will get warmer faster, without costing you anything extra. And as a bonus, when you’re saving energy, you’re also lowering your carbon footprint in the process.

Top tips for a more efficient boiler

Troubleshooting boiler issues that affect their efficiency is usually straightforward. If your hot water is taking a long time to heat, or your heating is inconsistent in its output, your boiler is likely not performing to the best of its ability. Not to mention, a sudden spike in your energy bills can also be a clear sign of an inefficient boiler, especially if you’re paying more and your usage is remaining consistent.

From checking the pressure to adjusting its settings, there are several easy ways you can get your boiler back to its working best as soon as you notice a drop in output.

Monitor boiler pressure

This is the simplest check you can carry out on your boiler. Regularly monitoring its pressure gauge will immediately let you know if there are any issues with your boiler. The pressure gauge indicates the pressure of the water circulating in the heating system. Your boiler’s ideal pressure is around 1 and 1.5 bar when the heating is not in use, usually indicated by a green section. However, don’t be alarmed if it rises to almost 2 bar and enters the red as water expands when it heats up, increasing the pressure.

If your boiler’s pressure is too high, it’s likely due to a faulty component such as the filling loop which can add too much water to the boiler if broken. If your gauge is showing the pressure to be unusually high, you should switch off the boiler and check the filling loop. If there are no issues with the system, allow the water in the boiler to cool down before bleeding a radiator and examining the pressure once again. If you’re not sure how to bleed a radiator, you can check out our guide for more information.

If the pressure is too low, your system will not be able to circulate hot water as effectively around your home. The most common cause of a dropping boiler pressure is a leak in your boiler; if there are no obvious signs of a leak around your boiler, there’s likely a hidden leak somewhere within your pipes. In this case, you should contact a professional Gas Safe engineer to detect the leak.

Insulate your pipes

Your boiler may be working at its best, but if your pipes are losing heat when your central heating is on, it could all be for nothing. Properly insulating your pipes will reduce heat loss and keep your water hotter throughout the house. To do this, all you need is foam tubes or lagging around your pipes, but always make sure you opt for ones that are safe to use around heat.

Insulating the pipes around your boiler will also reduce any standby heat loss when your boiler is not actively in use, reducing the amount of time it takes for the water to reach optimal temperature and circulate around your home.

Schedule regular maintenance

It’s always a good idea to arrange for a professional to carry out yearly maintenance on your boiler so that it’s always working at its best, especially when you need it the most. Check-ups like this mean that any faults can be caught before they become an issue, keeping your boiler in peak condition for longer.

You should schedule an expert to come and clean out the boiler system every so often as this will get rid of debris, rust, and sludge that has built up inside, blocking the flow of water. They will also refill the boiler with clean water and chemicals that prevent corrosion.

There’s also maintenance that you can carry out yourself too, such as bleeding your radiators. This releases trapped air from your heating system so that it’s easier for water to circulate properly and warm up your home faster.

Adjust the settings

Many homeowners make the mistake of having their boiler’s flow settings too high which results in wasted energy. Combi boilers are designed to run at a flow temperature of 70°C to 80°C, but they often work best running at just 60°C. Even during winter, your boiler will run efficiently between 60°C and 70°C. Turning this setting down means you’re not wasting energy and heating your boiler more than it’s necessary to heat your home.

A smart thermostat can tweak your heating settings to best fit in with your lifestyle. This gives you the option to set schedules and even heat singular rooms so that you’re never warming up the entire house when it’s not needed.

Switch it on over summer

Switching your boiler on over the summer might seem counterintuitive, but sometimes boilers can suffer in the winter when they’ve been left dormant for too long. All you need to do is turn it on for 15 minutes each week to prevent it from seizing up when you need it the most, making it less likely to have a breakdown later in the year.

Consider investing in a new boiler

If your boiler’s pressure continues to fluctuate significantly, or if insulating your pipes fails to improve performance, it may be time to consider investing in a new boiler. Boilers lose efficiency with age, so not only can a new boiler perform to the maximum of their efficiency rating, but modern boiler systems also come with the latest features, designed with efficiency in mind.

Newer boilers are often equipped with modulation technology, which is an effective means of improving boiler efficiency. By adjusting its energy output based on your usage, a modulating boiler will provide the exact amount of heat needed, reducing wasted energy.

Another reason to consider upgrading your boiler is to increase its size to match your needs. An undersized boiler won’t effectively fulfil your energy requirements, placing unnecessary strain on your boiler and your energy bills by requiring it to run constantly.

On the other hand, if your needs for hot water have permanently decreased, your boiler may now be too big. Unless you have a modulating boiler, you’re likely to be heating up an unnecessary amount of water, using more energy than needed, and ultimately resulting in a higher energy bill every month.

Whether you decide to invest in a new boiler or show your current system some love, an efficient boiler is a must-have as winter approaches. Having an efficient boiler is vital for keeping your home warm and cosy without breaking the bank.

If improving your home’s efficiency is your top priority this year, discover our collection of home efficiency solutions with our smart home range. And, if you found this article helpful, check out our other energy-saving advice pieces for more tips.