Boilers

Shop high-quality boilers from trusted brands like Ideal Boilers, Vokera, Vaillant and Baxi. At Toolstation, you’ll find gas combi boilers and system boilers compatible with most central heating systems.

What Are the Different Types of Boilers?

Combi boilers are a popular choice for many homes, heating water as you need it. They are smaller and more compact than system boilers, making them easier to install in any property.

System boilers store hot water in a cylinder after heating it, producing higher volumes on demand. They can be helpful for homes with two or more bathrooms. However, once the hot water supply has been used up, you’ll have to wait for the boiler to heat more.

Browse our full range of boilers and related accessories here, or check out our Boiler Buying Guide for more tips and advice on finding the right one for you.

 

How do I size a boiler for a house or building?

Boiler sizing depends on your heat load: number of radiators, insulation, number of bathrooms, and hot water demand. 
Use kW rating - oversize slightly rather than undersize, but avoid huge overspec. For instance, a mid-size home might need 24–30 kW for a combi boiler. Consult heat loss calculations or use a rule of thumb per radiator/room.

Can I swap one boiler brand for another?

Yes - in many cases you can - but ensure compatibility: flue position, gas supply, pipework routing, control connections, and warranty implications. Reusing existing mounting, boiler room layout, and condensate routes can reduce installation challenges.

How often should I service a boiler?

Servicing your boiler annually is standard for most boilers. Regular servicing helps maintain efficiency, catch faults early, ensure safety, extend lifespan, and keep the warranty valid. Also check for leaks, carbon monoxide safety, flue integrity, pressure, and proper burner operation.

Vokera Vokera Vokera / Vokera Unica MAX System Boiler 30kW
Save £120

£1087.54 was £1208.38

ex. VAT £906.28 Each

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Vaillant Vaillant / Vaillant ecoTEC Plus 625 25kW System Boiler Only Power

£1922.78

ex. VAT £1602.32 Each

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Worcester Bosch Worcester Bosch Worcester Bosch / Worcester Bosch Greenstar 30Ri Compact Regular LPG Boiler 30kW

£1691.95

ex. VAT £1409.96 Each

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

£1262.16

ex. VAT £1051.80 Each

Product options Select from 4 options
Made4Trade Made4Trade / Made4Trade Circular Flue Guard 280 x 165mm Plastic Coated
( 44 )

£13.28

ex. VAT £11.07 Each

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Baxi Baxi / Baxi Standard Horizontal Flue 685mm
( 17 )

£123.50 was £126.48

ex. VAT £102.92 Each

Worcester Bosch Worcester Bosch Worcester Bosch / Worcester Bosch Greenstar 27Ri Compact Regular Boiler 27kW

£1542.97

ex. VAT £1285.81 Each

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Viessmann Viessmann / Viessmann Vitodens 100/200-W Flue Fixing Bracket

£10.94

ex. VAT £9.12 Each

Electric Heating Company Electric Heating Company / EHC FUSION COMET Three Phase System Boiler 39kW

£2049.54

ex. VAT £1707.95 Each

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Vaillant Vaillant / Vaillant ecoMAX/TEC Elbow 90°

£74.54

ex. VAT £62.12 Each

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Viessmann Viessmann / Viessmann Vitodens Flue Extension 0.5m

£42.10

ex. VAT £35.08 Each

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Ideal Boilers Ideal Boilers / Ideal Logic Max Combi 2 Boiler 24kW

£1447.58

ex. VAT £1206.32 Each

Product options Select from 2 options
Baxi Baxi Baxi / Baxi 800 Combi 2 Boiler 24kW
Save £153
( 1 )

Product code: 62654

Baxi 800 Combi 2 Boiler 24kW

£1376.98 was £1529.98

ex. VAT £1147.48 Each

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Worcester Bosch Worcester Bosch Worcester Bosch / Worcester Bosch Greenstar 18Ri Boiler ErP+ LPG 18kW

£1404.33

ex. VAT £1170.27 Each

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Viessmann Viessmann / Viessmann Vitodens 100-W Combi Boiler 30kW

£1679.45

ex. VAT £1399.54 Each

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Vokera Vokera / Vokera Vision Plus Combi Boiler 30kW
Save £77
( 2 )

£700.86 was £778.73

ex. VAT £584.05 Each

Electric Heating Company Electric Heating Company / EHC SLIM JIM Electric Flow Boiler 14.4kW
Save £55

£849.00 was £904.28

ex. VAT £707.50 Each

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

£1788.44

ex. VAT £1490.37 Each

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Vokera Vokera Vokera / Vokera Unica MAX Combi Boiler 35kW
Save £213
( 1 )

£854.48 was £1068.10

ex. VAT £712.07 Each

Viessmann Viessmann / Viessmann Vitodens 100-W System Boiler 19kW

£1799.98

ex. VAT £1499.98 Each

Vaillant Vaillant / Vaillant ecoMAX/TEC Elbow 45°

£110.18

ex. VAT £91.82 Per unit £55.09/Each

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Ideal Boilers Ideal Boilers / Ideal Universal Weather Collar

£73.56

ex. VAT £61.30 Each

Talon Talon Talon / FS5 FlueSnug 100mm White

Product code: AE524

FS5 FlueSnug 100mm White

£14.99

ex. VAT £12.49 Each

Product options Select from 1 option
Made4Trade Made4Trade Made4Trade / Made4Trade Circular Flue Guard 280 x 165mm Zinc Plated Mild Steel
20% Off
( 20 )

£15.00 was £19.98

ex. VAT £12.50 Each

Product options Select from 1 option