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.
Product code: 48150
Baxi Standard Telescopic Horizontal Flue
£122.27 was £135.85
ex. VAT £101.89 Each
Product code: AH985
Worcester Bosch Greenstar 21Ri Boiler ErP+ LPG 21kW
£1447.69
ex. VAT £1206.41 Each
Select from 4 options
Product code: 47534
Viessmann Vitodens Flue Extension 0.5m
£42.10
ex. VAT £35.08 Each
Select from 1 option
Product code: 35227
Ideal Logic Flue Extension 0.5m
£65.03
ex. VAT £54.19 Each
Select from 2 options
Product code: 38325
Vaillant ecoMAX/TEC Adjustable Flue Support Clips
£74.62
ex. VAT £62.18 Per unit £24.87/Each
Product code: 12436
Ideal Logic Flue Extension 2m
£138.76
ex. VAT £115.63 Each
Select from 2 options
Product code: AH995
Worcester Bosch Greenstar 18Ri Boiler ErP+ LPG 18kW
£1404.33
ex. VAT £1170.27 Each
Select from 4 options
Product code: AH961
Worcester Bosch Greenstar 30i Compact System LPG Boiler 30kW
£1822.77
ex. VAT £1518.97 Each
Select from 1 option
Product code: AE721
EHC Comet PV Electric System Boiler 2-8kW
£1239.98
ex. VAT £1033.32 Each
Select from 2 options
Product code: AH966
Worcester Bosch Greenstar 27Ri Compact Regular Boiler 27kW
£1542.97
ex. VAT £1285.81 Each
Select from 1 option
Product code: 71418
EHC SLIM JIM Electric Flow Boiler 12kW
£799.00 was £861.84
ex. VAT £665.83 Each
Select from 4 options
Product code: 70574
Baxi Flue Extension 1m with Fixing Screws
£61.83 was £68.70
ex. VAT £51.52 Each
Select from 2 options
Product code: 68889
Baxi Plume Displacement Kit Extension and Brackets
£42.16
ex. VAT £35.13 Each
Select from 3 options
Product code: AH952
Worcester Bosch Greenstar 27i Compact System Boiler 27kW
£1675.04
ex. VAT £1395.87 Each
Select from 1 option
Product code: AE722
EHC Comet PV Electric System Boiler 7.2-14.4kW
£1359.98
ex. VAT £1133.32 Each
Select from 2 options
