Efficient Combi Boilers – Which is the highest efficiency?

Combi boilers are the most popular type of boiler in the UK and we would like to show you the 3 top/best rated and most efficient combination boilers which are available on the market.

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These are our top boilers in terms of, installation, efficiencies, operating costs, and maintenance/warranty periods and then the benefit is you can get a fixed price quote online now in under 20 seconds by clicking get a quote!

What Are Energy Saving Combi Boilers

The energy-efficient combi boiler, also known as a combination boiler, is becoming increasingly popular, and over 70% of households choose to install it alongside a more efficient flue system.

However, if you are looking at more green systems and you are thinking of installing solar water heating, it should be noted that many combination boilers are not compatible with solar heating systems and cannot be used as effectively with these types of heating from solar equipment. 

Energy Efficiency Cost and Benefits at a Glance:

The cost of installing a new best combi boiler is between £1700 and upwards of £4000 depending on the system you are switching from and the type of installation you require. 

This can be offset by the increased efficiencies as they are cheap enough to run while they keep you warm throughout the winter. Combi Boilers are fed their water from their main supply, which means they are much more efficient than other types of boiler, such as a gas boiler. 

This means that there is no need to install a separate storage for heating and a water supply tank, which makes them so much more efficient than other types of boilers. 

The best combi boilers are compact, require fewer pipes and do not require the additional installation of the water tank but would require the removal of said tank if you are switching from a regular boiler system.

Efficiencies of a Combi Boiler.

Combi boilers are indeed more cost-effective. They are so effective because they only heat the water they use, so they heat and cool more efficiently and are therefore more affordable. 

Combi boilers are a type of combined unit, which means they can heat your house and provide hot water without the need for a separate water tank or hot water storage cylinder. They tend to be more efficient when it comes to heating water on demand, as they combine two functions of your household into one compact system. 

This means that combined boilers can achieve incredibly high efficiency, which will not only help to reduce your carbon footprint, but could also reduce your energy costs. 

If you plan to replace your current boiler with a modern combi boiler, you can save energy costs over the course of a year. 

A combi boiler installed in a UK home can cover up to 90% of your household’s energy needs, with an average energy efficiency of 92%. 

In fact, the efficiency of a combi boiler is 92 percent lost in heat, meaning that only 8p of every pound spent on energy costs is wasted. Some systems such as the Viessmann Vitodens models can achieve a seasonal efficiency of up to 89%, an almost remarkable feat of engineering.

Top 3 Most Economical Boilers for 2023.

Compare Boiler Quote’s boiler and heating experts have compiled a list of the top 3 most efficient and cost-effective combi boilers in the UK. This is based not only on the efficiency rating but on the cost of boiler installation, maintenance and reliability or warranty period. All these boilers made our best combi boiler list too:

1.Viessmann Vitodens 100-W 30kW model

The top spot for the most energy efficient combi boiler of the year 2023, which produces the # 1 “best combination,” for most average-sized UK homes is the Viessmann Vitodens 100-W 30Kw. This is due to the price, the warranty, the efficiency, and the internal heat exchanger.

Vitodens 100-W 30kW Combi Gas Boiler Features:

• Band Rating: A Rated
• ERP Rating: A HEAT A WATER
• Efficiency Rating: 94%
• Standard Warranty: 10 years
• Output: 30kW
• Flow Rate: 12 l/min
• LPG Compatible: Yes
• Mounting: Wall mounted
• Typical Price: (inc VAT) £1,100
• Typical installation Cost: £500 – £1,000
• Typical Total Cost: £2,300 – £2,700

2. Ideal Logic Plus 24kW Combi Boiler.

With a 94% efficiency rating, and 9.9l/min flow rate, 7 year warranty included, the Ideal Logic plus is a highly efficient boiler with compact size and great reliability. The Ideal Logic Combi + C24 comes with a heating output of 24.2kW.  This allows the system to heat up to 10 radiators at once.

One of the main features of this particular boiler is its fully modulated operation for low outputs. What does this mean? Well, it means that it will only power and burn fuel for the amount of radiators you need heating, so if you only need half of your radiators heating, it will modulate for 5 radiators, saving you fuel and money!

Ideal Logic Plus 24kW Combi Gas Boiler Features:

• Band Rating: A Rated
• ERP Rating: A Heat A Water
• Efficiency Rating: 94%
• Standard Warranty: 7 years
• Output: 24kW
• Flow Rate: 9.9 l/min
• LPG Compatible: Yes
• Mounting: Wall Mounted
• Typical Price: (inc VAT) £800
• Typical installation Cost: (inc VAT)* £500 – £1,000
• Total Average Installed Cost: £2,100 – £2,500

3. Worcester Bosch Greenstar 4000 30kW Combi.

The Greenstar 4000 30Kw is a very efficient and compact system with the capacity to provide hot water for up to 4 bed 2 bathroom homes, making it the perfect family home boiler system.

This particular system has the feature of an ErP (Energy Related Product directive) rating of A for both heat and hot water, thanks to its high heating efficiency of 94% and respectable flow rate of up to 12.3 litres a minute. 

Worcester Bosch Greenstar 4000 30kW Combi Gas Boiler Features:

• Band Rating: A Rated
• ERP Rating: A HEAT
• Efficiency Rating: 94%
• Standard Warranty: 7 Years
• Output: 30 kW
• Flow Rate: 10.8 l/m
• LPG Compatible: Yes
• Mounting: Wall Mounted
• Typical Price: (inc VAT) £1,250
• Typical installation Cost: (inc VAT) £600 – £1,000
• Typical Total Cost: £2,250 – £2,650

Other Helpful Tips:

It is crucial to install the right performing boiler in your home, as combi boilers are available in a variety of sizes to meet a variety of heating energy needs.

These range from small to large heating capacities so it is important that you ask your heating engineer what size you need for your home. 

This is because a combi that is too small will not be able to meet your heating and hot water needs, while an over-powerful combi will ultimately drive up your energy costs. 

If you have plans to expand your home, add more residents, remodel attic space or add a conservatory, you will need a larger boiler to ensure it meets your long-term needs.

Unlike conventional boilers, which are also known as normal, traditional or conventional boilers, this boiler does not require any additional space for the tanks so again you could have more storage space with a combi system installed. 

There are many boilers that have warranties of 7 years or more, but normally you would want to see a boiler with an average warranty of at least 5 years when making your decision.

Where to get the best combi boiler for efficiency?

You can get a fixed price boiler quote online in under a minute using our quote calculator.

This is why we recommend Boiler Central as a supplier and fitter of boilers as they can offer you a new boiler quote with a huge 12 year warranty.

You could also consider the Viessmann Vitodens 050-w for a superb family system which will be reliable, efficient, easy to maintain, and a great family system for years to come. 

Thanks again for reading and we hope you enjoyed our information, please check back for more of the top tips on boilers in the U.K.