Combi Boiler Price Guide

Combi is short for combination boiler, which refers to its ability to supply both central heating and hot water. Unlike System or Regular boilers which rely on a hot water storage cylinder, combi will produce hot water on demand. They are more efficient and they’re also great space-savers as they don’t need a water tank. If you currently have a big unsightly water tank in your basement or cupboard, you’ll be able to get rid of it once you convert your central heating system to combi.

Also the hot water tank no longer limits you as to how much hot water you can have. With a combi you now have an endless on-demand hot water supply and there is no standby energy loss as the hot water is only produced in the amount that is required. Storing water in conventional heating systems means part of the energy evaporates in thin air.

No matter how well the hot water cylinder is insulated, some heat will always escape. With a combination boiler there is no such problem because it heats up the flow of water as and when needed.

Combi boilers prices comparison and reviews of the best selling models for the year of 2019. If you’re not quite sure which combi boiler you should choose for your size house, this article is not going to leave any stone unturned.

As a general rule for modern combi boilers, you can’t have a boiler that’s too big for your house because most recent models will provide heat output depending on demand. An upside of having a bigger boiler is that you get a more steady supply of hot water. It is, however, possible to make a mistake and choose a boiler that’s not sufficient for your home in which case you won’t have adequate heating and hot water. We don’t necessarily suggest you buy a bigger boiler than you need – the key is to choose an optimum size boiler.

How much is a combi boiler in 2019?

Combi boiler prices in 2019 start from £545 and may exceed £3,000 for larger models. This estimate doesn’t include boiler installation. Also, it’s not necessarily a good idea to base your buying decision purely on price. You need a compromise between the price, efficiency and heat output otherwise you may end up with a boiler that is not suited to your type of house – sounds like a costly mistake. To find out which boiler is right for your house, check this article, or scroll down for a general overview of heat output. Check out the data tables below for a full price comparison.

However, there are many other factors for choosing the right boiler such as:

  • Length of manufacturer’s warranty
  • Length of installer’s workmanship warranty
  • Efficiency and eco-friendliness
  • Maximum heat output
  • Dimensions

The following comparison tables will give you a general idea of what size boiler is suitable for your house. They are sorted by combi boiler price but you can rearrange the tables by any other metric you’re interested in. For example, with the new smart home technology on the rise, many homeowners are looking for combi boilers that are compatible with the OpenTherm protocol so that they slot into their smart home environment easily. Also, another important factor is the dimensions of the boiler. Compact boilers are much easier to hide away in a kitchen cupboard.

All prices are given without the installation cost so that you can evaluate the actual cost of a boiler. Installation price depends on many different factors. Get a free quote from us to find out the total cost of your boiler replacement.

Best combi boiler for a flat or maisonette

Heat OutputRatingWarrantyPriceDimensions, mmOpenTherm Compatible
Vokera Vision BoilerVokera Vision 30 C26kW A7 years £590.00715 x 405 x 248Kit Required
Ravenheat Combi BoilerRavenheat CS8025kW A2 years £590.00700 x 425 x 300Yes
Ferroli ModenaFerroli Modena HE Combi 27kW A5 years £599.00600 x 400 x 320Yes
Baxi 200Baxi 200 Combi24kW A3 years £630.00700 x 395 x 279Yes
Biasi InoviaBiasi Inovia Combi 25kW A5 years £650.00803 x 400 x 350Yes
Intergas HREDaikin D2CDN 24kw24kW A2 years £750.00590 x 400 x 256Yes
Intergas HREIntergas HRE 24/1818kWA7 years £750.00590 x 450 x 240Yes
Potterton PromaxPotterton Promax Combi 24kW A2 years £790.00750 x 450 x 345Yes
Glowworm EnergyGlow-worm Energy Combi 25kW A7 years £790.00700 x 390 x 280 Yes
Viesmann 100Viessmann Vitodens 100-W Combi 26kW A5 years £840.00700 x 400 x 350Yes
Vaillant Ecotec Vaillant ecoTEC Pro Combi 24kW A2 years £900.00720 x 440 x 338No
Worcester BoschWorcester Bosch Greenstar Combi 25kW A5 – 12 yr£970.00690 x 390 x 280No
Ideal VogueIdeal Vogue Max Combi 26kW A10 years £1,100.00740 x 445 x 330Kit Required

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Choice for Medium Size Houses

Heat OutputRatingWarrantyPriceDimensions, mmOpenTherm Compatible
Vokera CompactVokera Compact A Combi29kWA5 years£545.00715 x 405 x 248Yes
Biasi RivaBiasi Riva Plus Combi28kWA2 years£550.00803 x 400 x 350Yes
Ferroli Modena Ferroli Modena HE Combi32kWA5 years£675.00600 x 400 x 320Yes
Alpha E TecAlpha E-tec 2828kWA5 years£675.00712 x 440 x 255Yes
Ravenheat Combi BoilerRavenheat HE98S31kWA5 years£715.00700 x 400 x 300Yes
Potterton GoldPotterton Gold Combi33kWA2 years£795.00780 x 450 x 345Yes
Intergas HREIntergas HRE 36/3030kWA7 years £799.00710 x 450 x 240Yes
GlowWorm EnergyGlow-worm Energy Combi30kWA7 years£835.00700 x 390 x 280Yes
Viesmann 50Viessmann Vitodens 050-W Combi29kWA3 years£845.00700 x 400 x 350Yes
Ideal LogicIdeal Logic Max Combi30kWA10 years£1,025.00700 x 395 x 278Kit Required
Vaillant EcotecVaillant ecoTEC Plus Combi32kWA5 years£1,135.00720 x 440 x 338No
Keston CombiKeston Combi C3030kW A7 years£1,150.00700 x 400 x 285Yes
Baxi EcoblueBaxi Ecoblue 3333kWA5 years£1,215.00763 x 450 x 345Yes
Worcester BoschWB Greenstar CDi Compact32kWA5 – 12 yr£1,295.00680 x 390 x 280No

Options for Large Properties with High Demand

Heat OutputRatingWarrantyPriceDimensions, mmOpenTherm Compatible
Biasi InoviaBiasi Inovia Combi35kWA5 years£650.00803 x 400 x 350Yes
GlowWorm UltimateGlow-worm Ultimate3 Combi35kWA5 years£775.00740 x 418 x 300Yes
Ferroli ModenaFerroli Modena HE Combi38kWA5 years£790.00600 x 400 x 320Yes
Intergas BoilerIntergas HRE 36/4040kWA7 years£830.00710 x 450 x 240Yes
Potterton TitaniumPotterton Titanium Combi40kWA7 years£960.00780 x 450 x 345Yes
Ideal LogicIdeal Logic+ Combi35kWA7 years£1,000.00700 x 395 x 278Kit Required
Keston Combi BoilerKeston Combi C3535kWA7 years £1,100.00700 x 400 x 285Yes
Vokera LineaVokera Linea One Combi 38kWA5 years£1,150.00845 x 453 x 358Yes
Baxi EcoblueBaxi EcoBlue Advance Combi40kWA10 years£1,250.00763 x 450 x 345Yes
Atag ICViessmann Vitodens 200-W35kWA3 years£1,295.00850 x 450 x 375Yes
Vaillant Ecotec Vaillant ecoTEC Plus38kWA5 years£1,500.00720 x 440 x 338No
Worcester BoschWB Greenstar CDi Classic42kWA5 – 12 yr£1,600.00760 x 440 x 360No

Since this guide is aimed at consumers, we have to give you a full overview. As with any device, there are downsides to operating a combi boiler – you can’t run two showers or two taps at the same time. There is a limit to the water flow that it can produce and only the tap closest to the boiler will produce a meaningful stream of hot water. If you open another tap at the same time, you’re lucky to get a fine trickle of warm water. Thus this option is not suited for a large family that needs to run several showers in the morning. Otherwise you’d have to queue up and risk being late for work or school. Another downside is that if it breaks down, you will have no hot water because there is no cylinder to heat it up.

Nevertheless, during the last few years, combi boilers have established themselves as market leaders for domestic boiler installations. As the household sizes keep reducing globally, there’s less and less demand for heating systems that can produce multiple streams of hot water.

Combi are considered low pressure boilers. If your water mains is weak, you may struggle getting a steady enough stream of hot water. If this is the case, make sure you mention this when getting a boiler quote or survey. It’s still possible to install a combi, however, you are likely to need an additional central heating pump to help the low mains pressure and ensure you get steady shower.

If you have an older system with a tank in the attic (an open system that relies on gravity rather than water pressure), the pipework may be too dodgy to handle a new heating system. In this case you may have to consider a complete overhaul involving new copper pipes taking your property into the 21st century and making sure the pipes are reliable enough to handle pressure.

All these downsides of combi boilers can be easily overcome apart from the demand issue. If you know you need simultaneous hot water from multiple taps or showers, then Regular or System is the way to go. We can help you with that too, just talk to our advisor when you discuss your boiler quote.

Which Boilers are OpenTherm compatible?

OpenTherm is a protocol used by smart heating systems to facilitate communication between a boiler and a thermostat. This protocol was invented by Honeywell – one of the major global smart thermostat manufacturer. Most modern thermostat models now support OpenTherm including Nest, Drayton and Salus. Not all heating devices support OpenTherm, though.

For a general idea of boilers compatible with OpenTherm, have a look at the price tables below. As a general rule, Worcester Bosch and Vaillant are not compatible, although you can easily buy adaptors to make these brands compatible too. On a side-note, if you get a new combi boiler from Worcester or Vaillant and you install an OpenTherm adaptor yourself (as in, not by a qualified engineer) your manufacturer’s warranty may become void.

How long does a combi boiler last?

As you can see from the combi boiler prices table, most manufacturers will offer between 2 and 5 years manufacturer warranty. A few makers will offer 7 or 10 years. Generally, you can increase the warranty period by finding the correct boiler installer who’s got a special contract with the manufacturer allowing him to extend the nominal warranty period.

Having said that, a well-built, well-maintained modern combi boiler should last at least 15 years or more without significant repairs.

For example, if certain conditions are met, we can extend warranty of a Worcester Bosch boiler to up to 12 years. As for the lower end – in our opinion 2 years warranty is not enough to fill customer with confidence so we suggest you go for a boiler that comes with at least 5 years warranty.

New Boiler on Government Grant

Are there any Government grants or schemes available to alleviate the purchase and installation of a new boiler? There are a few options to look at but the opportunities have dwindled during the last few years.

There used to be the Green Deal government scheme that helped households upgrade their heating systems. It mainly centred around promoting environmentally friendly and renewable systems and getting a new boiler was possible if installed together with a renewable system such as solar water panels or ground source pump. The Green Deal has been phased out and no new jobs are accepted under this scheme.

More recently the UK Government introduced the Boiler Plus scheme. Although it won’t help you get a new boiler cheaper, it will significantly reduce the cost of keeping your house warm and cosy. As of April 2018, all new installations will have to come with an efficiency upgrade. This is a mandatory measure and your boiler installer can’t wriggle out of it.

The most obvious way to ensure the combi boiler is more efficient is to hook it up with a smart thermostat, however, Boiler Plus government scheme provides various options. They are:

  • Smart thermostats helping automate and optimise home heating
  • Boiler load compensation system
  • Flue gas recovery system to make sure all gas is burned efficiently
  • Weather compensation systems.

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  • Small monthly repayments

    Monthly repayments from as little as £9.99 a month*. This is often offset by the monthly savings on your energy bills, a direct result of an energy efficient boiler.

  • Flexible Plans

    We have finance plans to suit your budget. Our plans range from 2 years right up to ten years.

  • 0% Interest Free

    In addition to monthly payments, we also offer 0% interest for up to 2 years.

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††Estimated figures based on installing a new A-rated condensing boiler with a programmer, room thermostat and thermostatic radiator controls (TRVs) in a gas-heated detached home from an older boiler without controls. Savings will vary depending on the size and thermal performance of your home. Correct as at May 2015Source: Energy Saving Trust.

*Representative Example: Cash Price £2,100. Deposit Payable £1,327. Total Amount of Credit £773. Total Interest £425.80. Total Amount Repayable £2,525.80 Repayable by 120 monthly instalments of £9.99. Representative 9.9% APR (fixed). Rate of Interest 9.9% a year (fixed). Duration of Agreement 120 months. Subject to Status

**The 12 year warranty is only available for customers who have a Worcester Bosch boiler supplied and fitted by Glow Green Ltd and is subject to a Glow Care 100 service contract for the 12 year period.