Put together by the team at WarmZilla, a UK-based installer of combination boilers.
Combination boilers, or “combi boilers”, are the most common boiler in the UK. Having been installed in the majority of homes, they are a firm favourite among the British population. It is estimated that 19% of the UK’s greenhouse gas emissions come from warming up the places we live and work, with more than three-quarters of this coming from domestic buildings. The vast majority of houses in the UK rely on gas boilers, but the British Government has moved to phase these out in the next five years.
What makes them particularly useful is their ability to instantly heat water from the mains as soon as the shower or hot tap is in use. This makes them incredibly efficient. On top of that, they are also simple to install and maintain. As well as not requiring an additional water cylinder or tank, they can function on a variety of fuel sources making them versatile.
Combi boilers can run on natural gas, oil, liquid petroleum gas (LPG), electricity, and in the future, there is a lot of focus on combi boilers running on hydrogen as many manufacturers are building combi boilers that are already compatible with hydrogen if it does get mainstream use in the future. Hydrogen used as fuel in a boiler produces no carbon emissions, it is only the production of hydrogen that produces carbon.
As far as boilers go, they are some of the eco-friendliest heating devices in the industry. Be that as it may, you could argue that even the most capable boilers can only be so effective. Like most appliances, they rely on their owners in order to work optimally. So, we’ve put together some basic tips which will help make the most of your combination boiler, as well as reduce your carbon footprint in the process.

5 Tips to Improve the Efficiency and Lower the Carbon Footprint of Combi Boilers
1) Check, check and check your boiler again.
Do you know how often your boiler should be checked? Roughly, it needs an inspection by a qualified gas engineer once a year to check it’s not only in good working order but also producing energy at maximum efficiency.
The main things that are carried out on a boiler service are:
• Visual inspection
• Check for corrosion and leaks
• Ensure boiler seals are in good condition
• Check gas/oil pressure
• Test appliance to ensure the rate that the gas/oil is being burned is safe
• Combustion analysis
• Ensure correct operation of components and controls
The cost of annual boiler services vary depending on who carries it out and what kind of boiler you have, but on average the cost will be between £75 – £150 for a local heating company.
2) Timing is everything.
It’s tempting to leave your heating on 24/7. But if you leave the boiler simmering away for every minute of every day, your heating bill will go through the roof. Set your heating on a timer so that it’s on when you’re home and off when you’re not.
Try setting it to activate twenty minutes before you need it and twenty minutes after you leave the house or head off to bed. This way you’ll save endless energy, as well as hundreds of pounds a year.
Installing a smart thermostat is always a good investment. A smart thermostat can save you money by learning your heating habits and adjusting the temperature of your rooms to suit your usage. Used in conjunction with Thermostatic Radiator Valves (TRVs), they can make sure that there is no wasted spend on your heating bill.
Thermostatic Radiator Valves (TRVs) are valves that are installed on radiators that allow you to set the temperature for each individual room. You can save money by setting the temperature to a lower setting in rooms that you don’t use as often. By giving you more control of your heating you can lessen the work your boiler has to do to heat your home – again, saving you money on your gas bill. Imagine how much gas you could save if you could regulate the temperature on every radiator in the house to exactly what is required.
There is an initial outlay on a smart thermostat but as with TRV’s, you will soon recoup the initial outlay on reduced heating bills as well as enjoying your ideal temperature in each room.
Heating experts say that a smart thermostat will “pay for itself within a year” by reducing your heating bills and for all the tech-savvy folk out there, you can control your smart thermostat on your smartphone!
A smart thermostat is connected to your home Wi-Fi, allowing you to control your heating from a phone app, so you can pre-heat your home when you need to.
3) Turn the temperature down.
It’s vital to make sure you are always warm enough, but if you can accomplish this with a woolly jumper instead of switching the heating on then you’ll be doing your finances a huge favour in the long run. According to the UK and Ireland Fuel Distributors Association Ltd (UKIFDA), turning your thermostat down on your boiler by just one degree cuts fuel consumption by up to 10%.
4) Minimise draught.
Draughty areas in your home can be responsible for a significant amount of heat loss, which means you must spend more on heating to keep your house warm. Windows and doors are the main areas where you lose heat. Fitting draught excluders are a cost-effective way of reducing draughts and lowering your energy bills. Thermal leak detectors are useful for identifying the areas where your house is losing heat and with so many on the market, they don’t have to break the bank either.
Eliminating draughts will allow you to drop your thermostat down a degree or two. Decreasing the temperature of your thermostat by one degree is believed to be able to save you £80 a year. Yes, you’ve read that right!
A lot of heat is also lost through windows. Even with double glazed windows, this can occur. Try closing the curtains/blinds earlier or purchase thicker curtains. It can make a surprisingly big difference.
5) Keep an eye on your radiators.
Do you need to heat all the rooms in your house? What about that spare room you never use? By the side of your radiators, a dial will control how much heat emanates from them whenever they are switched on. If you turn this down in the rooms you don’t use, it’s less hassle on your combination boiler, which means more money in your pocket.
So to recap, a combination boiler is already a highly powerful heating system, which works extremely hard to keep the home free of any serious cold spots. However, in light of the current energy shortage, it’s important to use energy smartly. Making homes more energy-efficient will help all of us avoid feeling hot under the collar from increasing bills in the foreseeable future.