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Combi Boilers

Shop high-performance combi boilers from trusted brands at Toolstation, including Vokera, Ideal Boilers, Vaillant, Viessmann and Baxi. Whether you... 

Shop high-performance combi boilers from trusted brands at Toolstation, including Vokera, Ideal Boilers, Vaillant, Viessmann and Baxi. Whether you need a small combi boiler for your home or an industrial combi boiler for the workplace, we’ve got plenty of products available.

What is a Combi Boiler?

A combi (combination) boiler gives you heating and hot water straight from one compact unit. No tanks, no cylinders – it heats water as you need it. Perfect if you want to save space and keep the job simple.

What size combi boiler do I need?

It depends on the job:

  • Small homes or flats (up to 10 rads) – go for 24–27 kW
  • Medium homes (up to 15 rads) – 28–34 kW
  • Bigger jobs with more bathrooms – 35–42 kW

Get it right and you’ll have enough hot water and heat without overworking the boiler.

 

Are combi boilers energy‑efficient?

Yes. Most new combis are A‑rated and run at 90%+ efficiency. That means less fuel wasted and lower bills. Fit it right, set it up properly, and it’ll run efficiently.

Are combi boilers suitable for flats or small homes?

Yes. Combi boilers are built for places where space is tight. With no need for a hot water cylinder, you can fit one neatly in a cupboard or kitchen unit.

How long do combi boilers last?

On average, combi boilers 10–15 years with regular servicing. Look after it, flush the system when needed, and replace worn parts early to keep it running longer.

What Is the Best Combi Boiler?

If you’re wondering how to choose the right combi boiler, there are a few factors to consider. As a general rule, the more hot water you use, the higher the kilowatt rating you’ll need. For example, if you live in a flat or house with up to ten radiators and one bathroom, a 24-27kw combi boiler is the ideal choice. For homes with up to fifteen radiators and two bathrooms, a 28-34kw combi boiler is best. Large homes or businesses with up to twenty radiators and two or more bathrooms should opt for a 35-42kw boiler. Combi boilers are often the most energy-efficient choice in any central heating system, with options available to suit all budgets and home configurations. Check out our Boiler Buying Guide for more details on these and other boilers.

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VokeraVokeraVokera / Vokera Vibe MAX Combi Boiler 26C 25kW
( 13 )

Product code: 36777

Vokera Vibe MAX Combi Boiler 26C 25kW

£638.99

ex. VAT £532.49Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 2000 Combi Boiler 30kW

Product code: AH982

Worcester Bosch Greenstar 2000 Combi Boiler 30kW

£1206.49

ex. VAT £1005.41Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 1000 Combi Boiler 30kW

Product code: AH981

Worcester Bosch Greenstar 1000 Combi Boiler 30kW

£910.00

ex. VAT £758.33Each

Worcester BoschWorcester Bosch / Worcester Greenstar Combi 4000 Boiler 30kW
Save£26

Product code: 82864

Worcester Greenstar Combi 4000 Boiler 30kW

£1573.49Was £1599.98

ex. VAT £1311.24Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 24Ri Boiler ErP+ LPG 24kW

Product code: AH989

Worcester Bosch Greenstar 24Ri Boiler ErP+ LPG 24kW

£1551.99

ex. VAT £1293.32Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 1000 Combi Boiler 24kW

Product code: AH972

Worcester Bosch Greenstar 1000 Combi Boiler 24kW

£840.00

ex. VAT £700.00Each

VokeraVokeraVokera / Vokera Pinnacle Combi Boiler 35kW
( 1 )

Product code: 73228

Vokera Pinnacle Combi Boiler 35kW

£1081.99

ex. VAT £901.66Each

VaillantVaillant / Vaillant ecoFIT Pure 825 Combi Boiler with Flue and Magnetic Filter 25kW
( 3 )

Product code: 34270

Vaillant ecoFIT Pure 825 Combi Boiler with Flue and Magnetic Filter 25kW

£1658.49

ex. VAT £1382.07Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 2000 Combi LPG Boiler 30kW

Product code: AH984

Worcester Bosch Greenstar 2000 Combi LPG Boiler 30kW

£1273.49

ex. VAT £1061.24Each

Ideal BoilersIdeal Boilers / Ideal Logic+ Combi 2 Boiler ErP C30 30kW

Product code: 36378

Ideal Logic+ Combi 2 Boiler ErP C30 30kW

£1349.99

ex. VAT £1124.99Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 8000+ Combi Boiler 45kW

Product code: AH979

Worcester Bosch Greenstar 8000+ Combi Boiler 45kW

£2756.00

ex. VAT £2296.67Each

VaillantVaillant / Vaillant ecoFIT Pure 835 Combi Boiler with Flue and Magnetic Filter 35KW

Product code: 20935

Vaillant ecoFIT Pure 835 Combi Boiler with Flue and Magnetic Filter 35KW

£1868.49

ex. VAT £1557.07Each

BaxiBaxi / Baxi 600 Combi 2 Boiler Range 24kW
( 1 )

Product code: 45331

Baxi 600 Combi 2 Boiler Range 24kW

£1009.49

ex. VAT £841.24Each

Ideal BoilersIdeal Boilers / Ideal Logic+ Combi 2 Boiler ErP C24 24kW
( 1 )

Product code: 85188

Ideal Logic+ Combi 2 Boiler ErP C24 24kW

£1169.49

ex. VAT £974.57Each

Worcester BoschWorcester Bosch / Worcester Greenstar Highflow 440CDi Floor Standing Combi Boiler 29kW

Product code: AH957

Worcester Greenstar Highflow 440CDi Floor Standing Combi Boiler 29kW

£3148.49

ex. VAT £2623.74Each

VaillantVaillant / Vaillant ecoTEC Plus 940 Combi Boiler 40kW (2 Boxes)

Product code: AI006

Vaillant ecoTEC Plus 940 Combi Boiler 40kW (2 Boxes)

£2765.49

ex. VAT £2304.57Each

VaillantVaillant / Vaillant ecoTEC Plus 840 40kW Combi Boiler Only Power

Product code: 98543

Vaillant ecoTEC Plus 840 40kW Combi Boiler Only Power

£2412.49

ex. VAT £2010.41Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 36CDi Compact Combi Boiler 36kW

Product code: AH951

Worcester Bosch Greenstar 36CDi Compact Combi Boiler 36kW

£2067.99

ex. VAT £1723.32Each

BaxiBaxi / Baxi 800 Combi 2 Boiler 30kW
( 4 )

Product code: 31740

Baxi 800 Combi 2 Boiler 30kW

£1563.49

ex. VAT £1302.91Each

VaillantVaillant / Vaillant ecoTEC Plus 832 32kW Combi Boiler Only Power

Product code: 87909

Vaillant ecoTEC Plus 832 32kW Combi Boiler Only Power

£2139.49

ex. VAT £1782.91Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 8000+ Combi LPG Boiler 40kW

Product code: AH983

Worcester Bosch Greenstar 8000+ Combi LPG Boiler 40kW

£2403.00

ex. VAT £2002.50Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 8000+ Combi Boiler 32kW

Product code: AH978

Worcester Bosch Greenstar 8000+ Combi Boiler 32kW

£1865.00

ex. VAT £1554.17Each

ViessmannViessmann / Viessmann Vitodens 050 Combi Boiler 30kW

Product code: AH922

Viessmann Vitodens 050 Combi Boiler 30kW

£1294.32

ex. VAT £1078.60Each

GlowwormGlowworm / Glowworm Energy Combi Boiler 30kW

Product code: AH912

Glowworm Energy Combi Boiler 30kW

£1410.00

ex. VAT £1175.00Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 28CDi Compact Combi Boiler 28kW

Product code: AH954

Worcester Bosch Greenstar 28CDi Compact Combi Boiler 28kW

£1562.99

ex. VAT £1302.49Each

VokeraVokeraVokera / Vokera Pinnacle Combi Boiler 30kW
( 1 )

Product code: 81799

Vokera Pinnacle Combi Boiler 30kW

£999.99

ex. VAT £833.32Each

VokeraVokeraVokera / Vokera Synergy Combi Boiler 30kW
( 1 )

Product code: 95889

Vokera Synergy Combi Boiler 30kW

£875.99

ex. VAT £729.99Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 2000 Combi Boiler 25kW

Product code: AH986

Worcester Bosch Greenstar 2000 Combi Boiler 25kW

£1062.49

ex. VAT £885.41Each

VokeraVokeraVokera / Vokera Unica MAX Combi Boiler 35kW
( 1 )

Product code: 97217

Vokera Unica MAX Combi Boiler 35kW

£961.64

ex. VAT £801.37Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 32CDi Compact Combi Boiler 32kW

Product code: AH953

Worcester Bosch Greenstar 32CDi Compact Combi Boiler 32kW

£1762.49

ex. VAT £1468.74Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 12Ri Boiler ErP+ 12kW

Product code: AH987

Worcester Bosch Greenstar 12Ri Boiler ErP+ 12kW

£1247.99

ex. VAT £1039.99Each

VaillantVaillant / Vaillant ecoTEC Plus 836 36kW Combi Boiler Only Power

Product code: 38523

Vaillant ecoTEC Plus 836 36kW Combi Boiler Only Power

£2265.49

ex. VAT £1887.91Each

Ideal BoilersIdeal Boilers / Ideal Vogue Max Combi Boiler 40kW
( 1 )

Product code: 10268

Ideal Vogue Max Combi Boiler 40kW

£2077.99

ex. VAT £1731.66Each

VokeraVokeraVokera / Vokera Vibe MAX Combi Boiler 30C 30kW
( 13 )

Product code: 27309

Vokera Vibe MAX Combi Boiler 30C 30kW

£682.99

ex. VAT £569.16Each

VaillantVaillant / Vaillant ecoFIT Pure 830 Combi Boiler with Flue and Magnetic Filter 30kW

Product code: 21888

Vaillant ecoFIT Pure 830 Combi Boiler with Flue and Magnetic Filter 30kW

£1731.99

ex. VAT £1443.32Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 8000+ Regular LPG Boiler 40kW

Product code: AH964

Worcester Bosch Greenstar 8000+ Regular LPG Boiler 40kW

£2747.99

ex. VAT £2289.99Each

Worcester BoschWorcester Bosch / Worcester Bosch EasyControl CT 200 Black

Product code: AE567

Worcester Bosch EasyControl CT 200 Black

£204.48

ex. VAT £170.40Each

VokeraVokeraVokera / Vokera Pinnacle System Boiler 32kW

Product code: 73667

Vokera Pinnacle System Boiler 32kW

£1183.99

ex. VAT £986.66Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 2000 Combi LPG Boiler 25kW

Product code: AH977

Worcester Bosch Greenstar 2000 Combi LPG Boiler 25kW

£1146.49

ex. VAT £955.41Each

Worcester BoschWorcester Bosch / Worcester Greenstar Combi 4000 Boiler 25kW

Product code: 28922

Worcester Greenstar Combi 4000 Boiler 25kW

£1474.49

ex. VAT £1228.74Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 8000+ Regular Boiler 30kW

Product code: AH967

Worcester Bosch Greenstar 8000+ Regular Boiler 30kW

£1922.49

ex. VAT £1602.07Each

BaxiBaxi / Baxi 800 Combi 2 Boiler 36kW
( 4 )

Product code: 13762

Baxi 800 Combi 2 Boiler 36kW

£1794.00

ex. VAT £1495.00Each

GlowwormGlowworm / Glowworm Energy Combi Boiler 35kW

Product code: AH917

Glowworm Energy Combi Boiler 35kW

£1589.99

ex. VAT £1324.99Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 27i Compact System Boiler 27kW

Product code: AH952

Worcester Bosch Greenstar 27i Compact System Boiler 27kW

£1753.49

ex. VAT £1461.24Each

BaxiBaxi / Baxi 800 Combi 2 Boiler 24kW
( 1 )

Product code: 62654

Baxi 800 Combi 2 Boiler 24kW

£1386.99

ex. VAT £1155.82Each

Ideal BoilersIdeal Boilers / Ideal Logic Max Combi 2 Boiler 35kW
( 2 )

Product code: 11793

Ideal Logic Max Combi 2 Boiler 35kW

£1921.99

ex. VAT £1601.66Each

Worcester BoschWorcester Bosch / Worcester Bosch Greenstar 4000 Combi LPG Boiler 25kW

Product code: AI001

Worcester Bosch Greenstar 4000 Combi LPG Boiler 25kW

£1570.99

ex. VAT £1309.16Each

BaxiBaxi / Baxi 600 Series Combi 2 Boiler 36kW

Product code: 71310

Baxi 600 Series Combi 2 Boiler 36kW

£1304.99

ex. VAT £1087.49Each