Combi boiler prices 2021 - we compare 77 boiler models

 

Who offers the best combi boiler prices in 2020?

Combi boiler prices range from around £600 for a small, entry-level boiler to nearly £2,000 for a large, premium range model. Average prices are around £700 - £900. We compare combi boiler prices and review the merits of 77 models of boilers from 11 manufacturers: Worcester, Vaillant, Baxi, Viessmann, Intergas, Ravenheat, Potterton, Main, Glow-Worm, Ferroli and Ideal in the ULTIMATE guide to combi boiler prices.

Find your best combi boiler

The aim of this guide is to help you find the most suitable combi boiler for your property's size and your budget. This guide considers groups of combi boiler according to budget, we have four: Entry level (cheapest), Economy (one up from entry level), Mid-Range and Premium, the most expensive. 

Warning...even 'the best' combi boiler is not A-rated out of the box

Combi boilers are not A-rated out of the box, they require a competent installer to set them up correctly and 99% of installers have not been trained to do this. Whilst we guide you on best buys and best performance, they will only fulfil their potential if fitted by an installer trained in correct heating system design principles. Find out more about our work to deliver A-rated heating systems at our Heating Heroes page.

How we award our Best Buys and Best Performance

We have weighed up the boiler warranty, price, output and efficiency to see if there are any clear 'best buys' in each group. In both the Entry Level and Economy groups there are clear winners that offer a great all round package at a great price. In the Mid Range and Premium groups there are clear best buys but there are also some Best Performance category boilers.

Results Overview

We have found that not all manufacturers produce a boiler model for each of our budget groups. Where a manufacturer is not listed in the group they quite simply do not have a boiler in that price range. For example, Vaillant do not produce an Entry Level or Economy boiler model whilst Ferroli only produce an Entry Level boiler model.

The tables below also include some key data on heating out puts and domestic hot water flow rates. It is important to remember that for many combination boilers the heat output is the same for all of the model sizes, it is only the hot water flow rate that increases on the ‘larger’ models. So for example, the Ideal Independent comes in C24, C30 and C35 models. The heating output is 24kW for all of them, only the hot water flow rates vary: 9.9 LPM, 12.4 LMP and 14.5 LPM respectively. In other words, the model ‘number’ is not always an indication of heat output, although it occasionally is (confusing we know).

Entry level combi boilers

There are some great performing boilers in this category and many outperform the economy and some of the mid range models. Check out Ravenheat for truly great efficiencies!

1 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Baxi 200	224	£620	3	3	22kW	9.8	5.2kW
Ravenheat	HE80	£649	5	5	21KW	10.2	3.6kW
Baxi 400	424	£670	5	5	22kW	9.8	5.2kW
Ideal Independent	C24	£670	5	5	24KW	9.9	4.8kW
Main Eco Elite	25	£525	5	5	24KW	10.2	6.7kW
Glow Worm Easicom	24	£520	3	5	24KW	10	5.3kW

1-2 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Baxi 200	228	£570	3	3	28KW	11.5	5.2kW
Alpha Evoke	28	£670	5	10	28KW	12.1	4.3kW
Ideal Independent	C30	£745	5	5	24KW	12.3	6.2kW
Main Eco Elite	30	£570	5	5	30KW	12.3	9.4kW
Glow Worm Easicom	28	£550	3	5	25KW	11.7	6.3kW
Ferroli/Modena	27KW	£630	5	5	24KW	11.1	6.2kW

2 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Ideal Independent	C35	£805	5	5	24KW	14.5	7.1kW
Ravenheat HE	98S	£719	5	5	26KW	12.1	3.7kW
Potterton Titanium	28	£790	7	7	25kW	11.5	9.5kW
Ferroli/Modena	32KW	£670	5	5	28KW	14.1	7.2kW

2 bathrooms in use at the same time

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Potterton Titanium	40	£930	4	7	32KW	16.4	12.1kW
Ferroli/Modena	38KW	£815	5	5	34KW	16	7.0kW

Economy combi boilers

The majority of our Economy combi boilers range between £700 and £800 for the smaller models and £800 and £900 for the larger models, with only the very large 32kW boilers going a bit higher.

The boilers in this category tend to offer longer warranties but many of the entry-level boilers outperform them. That said, the Worcester 2000 is a great all-round package from this popular manufacturer.

1 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Baxi/Duotec	24	£750	7	7	21kW	9.8	7.4kW
Potterton/Titanium	24	£715	7	7	21kW	9.8	7.4kW
Worcester Greenstar 2000	25	£780	5	10	20kW	10.0	4.8kW

1-2 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Baxi/Duotec	28	£885	7	7	24kW	11.5	9.5kW
Glow Worm/Energy	25KW	£700	7	7	25kW	12.1	5.3kW
Potterton/Titanium	28	£790	7	7	25kW	11.5	9.5kW
Worcester Greenstar 2000	30	£740	5	10	30kW	12.0	4.8kW

2 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Baxi/Duotec	33	£990	7	7	28kW	13.5	10.2kW
Glow Worm Energy	30KW	£800	7	7	25kW	14.2	6.3kW
Potterton/Titanium	33	£855	7	7	28kW	13.5	10.2kW

2 bathrooms in use at the same time

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Baxi/Duotec	40	£1,045	7	7	34KW	16.4	12.1kW
Glow Worm Energy	35KW	£900	7	7	27kW	16.5	7.5kW
Potterton/Titanium	40	£930	7	7	32KW	16.4	12.1kW

 

 

Mid range combi boilers

We have found Mid Range boilers a much harder group to define. Prices for the small and medium models vary between £800 and £1100 and for the larger models between £900 and £1150. Almost all come with at least a 7 year warranty. It seems that the manufacturers that offer 10 year warranties do charge more for their boilers in these groups.

1 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Worcester Bosch Greenstar	25i	£940	5	10	24kW	10.2	8.2kW
Intergas Xclusive	24	£969	10	10	24kW	10.1	3.6kW
Worcester Bosch Greenstar	25Si	£1,045	7	10	24kW	9.8	8.1kW
Baxi EcoBlue Advance	24	£1,020	10	10	20kW	9.8	4.9kW
Valliant/EcoTEC pro	24	£965	2	7	24kW	9.6	5.2kW
Ideal/Logic + Combi	C24	£825	7	7	24kW	9.9	7.1kW
Viessmann Vitodens 100-W	26KW	£1,070	5	10	24kW	8.9	4.7kW

1-2 bathroom properties

6Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Worcester Bosch Si	30Si	£1,170	5	10	24KW	11.5	7.0kW
Baxi/EcoBlue Advance	28	£1,170	10	10	25kW	11.5	6.0kW
Vaillant EcoFIT Pure	830	£1,110	2	7	26KW	12.4	6.3kW
Vaillant EcoTEC Pro	28	£1,070	2	7	26KW	11.1	6.9kW
Vaillant EcoTEC Pro	30	£1,160	2	7	25kW	12.3	6.2kW
Ideal Logic +	C30	£890	7	7	24KW	12.4	6.1kW
Viessmann Vitodens 100-W	30KW	£1,115	5	10	30KW	11.2	5.8kW

2 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Baxi EcoBlue Advance	33	£1,300	10	10	28kW	13.5	7.1kW
Valliant EcoFIT Pure	835	£1,140	2	7	25kW	14.4	7.5kW
Ideal Logic+C35	C35	£1,035	7	7	24kW	14.5	7.1kW
Viessmann Vitodens 100-W	35kW	£1,090	5	10	32kW	13.5	5.4kW

Premium combi boilers

The Premium boiler group sees some much bigger variations in price. For the smaller models, prices range from £850 to around £1100, with only the Viessmann going significantly higher due to, we understand, technological superiorities. 

At the larger end, prices range between £1,200 and nearly £2,000. Model in this range of boilers are high performance and often aimed at larger properties. Nearly all come with a standard warranty of over 7 years.

1 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Worcester Greenstar 8000	30	£1,275	5	10	30kW	12.3	3.0kW
Baxi Ecoblue Advance	24	£1,020	10	10	20kW	9.8	4.9kW
Baxi Platinum	24	£1,110	10	10	24kW	9.8	7.4kW
Vaillant EcoTEC Plus	825	£1,145	5	10	19kW	10.5	3.8kW
Viessmann Vitodens 200-W	26	£1,602	3	10	26kW	10.7	1.9kW
Ideal Vogue	C26	£1,005	10	10	18kW	10.6	4.0kW
Intergas Xtreme	24	£1,209	7	7	20kW	11.0	3.6kW

1-2 bathroom properties

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Worcester Greenstar 8000	30	£1,275	5	10	30kW	12.3	3.0kW
Intergas Xtreme	30	£1,268	7	7	26KW	13.3	3.6kW
Vaillant EcoTec Plus	832	£1,290	5	10	25KW	13.0	5.2kW
Baxi Ecoblue Advance	28	£1,070	10	10	24KW	11.5	6.0kW
Baxi Platinum	28	£1,010	10	10	28KW	11.5	9,5kW
Ideal Vogue	C32	£1,115	8	10	26KW	13.1	4.6kW
Viessmann Vitodens 100-W	30KW	£1,115	5	10	30kW	11.2	5.8kW

2 bathroom properties

90Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Intergas Xtreme	36	£1,389	7	7	32KW	14.5	3.6kW
Worcester Greenstar 8000	35	£1,405	5	10	35kW	14.3	3.5kW
Baxi Ecoblue Advance	33	£1,300	10	10	28kW	13.5	7.1kW
Baxi Platinum	33	£1,145	10	10	28kW	13.5	10.2kW
Vaillant ecoTEC plus	832	£1,290	5	10	24kW	13.0	5.2kW
Vaillant ecoTEC plus	835	£1,470	5	10	30kW	14.3	5.8kW
Vaillant ecoTEC Green iQ	835	£1,651	5	10	25kW	14.5	3.4kW

2 bathrooms in use at the same time

Manufacturer/Model	Code	Price	Standard Warranty	Free Extended Warranty	Max Heating Output	Litres per minute for hot water	Min Heating Output
Viessmann Vitoden 200	25	£1,602	3	5	25kW	15.7	1.9kW
Vaillant ecoTEC plus	838	£1,440	5	10	29KW	15.9	6.5kW
Worcester Greenstar 8000	40	£1,600	5	10	35kw	16.4	3.5kW
Baxi Platinum	40	£1,260	10	10	40KW	16.4	12.1kW
Vaillant ecoTEC Green iQ	843	£1,700	5	7-10	33KW	17.8	4.3kW
Ideal Vogue	C40	£1,225	8	10	32KW	16.4	5.7kW

When is a combi boiler right for my home?

Combi boilers are not a one-size-fits-all solution, although they are often treated like they are. Combi boilers have big outputs because they are they sized for hot water and this has efficiency implications for heating. There are two main things to consider for combi boilers, even if you are replacing an existing combi:

What is a combi boiler?

A combi boiler is a single, usually wall hung, unit that supplies heating and instantaneous hot water to the home. Combi boilers do not require any water tanks for stored water. One of their advantages is their compact size. This can free up space in an airing cupboard for example when converting from a system with a hot water cylinder. The hot water flow rates on boilers can vary enormously and it is important to consider the flow rate as well as the heating output. If you have more than one bathroom then consider a higher hot water flow rate.

Important considerations

1) Do you have adequate water pressure and internal flow rates

These will determine whether a combi boiler will work. Both can be checked by an engineer when surveying for a new boiler. If your incoming pressure is good and internal flow rates are above 9 litres per minute (LPM) then a combi boiler will be suitable. It is worth noting that if your internal flow rates are at the lower end, 9-12 litres per minute, then only install a combi boiler with a matching flow rate capability.

The tables below show Litres Per Minute for Hot Water in the second column from the right. There is no point paying for a boiler capable of 16 litres per minute if you only have flow rates of 10 LPM, so choose carefully. You should also be mindful of your hot water requirements. Hot water flow rates from the boiler will be halved when two hot water outlets are on at the same time. If two or more showers run simultaneously in the mornings, for example, go with a boiler with a higher flow rate or opt for a system boiler with hot water tank.

2) The size of your property verses hot water demand

As outlined above, if you have multiple bathrooms then you can opt for a larger combi boiler. However, you need to separate the heating requirement from the hot water requirement. You will note that combi boilers are after 24kW or 36kW, this is because the boiler will need to output at 24kW to achieve say 10 LPM for hot water and 36kW to achieve 16 LPM for example. For heating, however, 24kW and 36kW is greater than you will ever need to heat your home. It is common for the heating output of a combi boiler to be much lower, 18kW or 20kW for example, but that is still usually much more than is needed. The average UK home only needs 6-8kW to keep it warm in cold weather.

The good news is that some boilers can, and must, be 'range rated' down on the heating side whilst keeping the higher capacity on the hot water side. An 18kW heating boiler will usually output between 5-18kW, therefore the engineer can range rate it down to 8kW, for example, to better meet your heat requirement. The dangers of leaving it at 18kW is the boiler will never achieve 90% efficiency and you will experience higher fuel bills. The other way to get overcome this is to not have a combi and go with a system boiler using a 'priority hot water' set up.

For more help sizing your boiler read guide to Sizing your Boiler.

Combi boilers for bigger homes

Combi boilers are available that offer upto 25 litres per minute - see table below. These tend to be floor-standing models. For bigger properties, it is also worth considering a system boiler with a hot water tank located near your bathrooms. Where your incoming water pressure is quite poor, or you just need more power, hot water performance can be boosted with the use of 'accumulator' tanks. These store the water from the mains and pass onto the hot water tank at a high rate. In this way they can convert water that comes into the property at say 10 litres per minute to 25 litres per minute or higher.

Price band		Cupboard fit	Boiler cost	Manufacturer Cover	Warranty or Guarantee	Efficiency	Litres per minute hot water
£££	Vaillant ecoTEC plus 938 storage combi	N	£ 1,610	7-10	G	89%	20.0
££££	Vaillant ecoTEC Green iQ 843	N	£ 1,700	7-10	G	94%	17.8
££££	Worcester Highflow 440CDi	N	£ 2,115	5-10	G	92%	20.0
££££	Worcester Highflow 550CDi	N	£ 2,480	5-10	G	92%	25.0
££££	Worcester Greenstar 8000 45	N	£1,905	5-10	G	94%	18.3