
Gas heat only boilers, also sometimes known as open vent boilers, provide heat to radiators and a hot water cylinder. Hot water is heated over a period of time and then stored in a hot water cylinder for use when needed, unlike a combi boiler which heats water instantaneously. As a result heat only boilers generally require less power output than a combi; a typical heat only boiler will be 15-20kW output rather than a minimum of 24kW output for a combi. Heat only boilers are also generally simpler and lower priced than system boilers. A system boiler has additional components built into the unit whereas a heat only boiler relies on external components such as a pump to circulate water round the system.
The choice between an heat only boiler or a system boiler is often driven by ease of installation. In an existing installation where the existing external components, such as the Grundfos pump shown in the photo, do not require replacement then a heat only boiler is a lower cost choice. System boilers have not been around so long so most existing installations will be using a heat only boiler. Where a totally new installation is being done then a system boiler may make more sense as the installer does not have to buy or install additional components.
Below we list the popular heat only boiler options by power output in kW and then brand. Note that the prices are for the boiler only and do not include the flue. They are also typical prices and do not reflect any price promotions with a specific plumbers merchant or retailer. On occasions, manufacturers offer promotional packages which include the flue.
See also prices for: System Boilers and Combi Boilers.
If you want an indication of what you may pay for a boiler replacement including installation then use our replacement boiler cost online calculator. You can then compare any quotations from installers with this guideline estimate.
Power Output | Product | Typical price inc VAT | Warranty Period Years * | Technical Details |
---|---|---|---|---|
9kW | Worcester Bosch Greenstar 9Ri | £887.29 | 5 | View |
12kW | Baxi 200 Heat 12 | £766.78 | 3 | View |
12kW | Baxi 400 Heat 12 | £785.56 | 3 | View |
12kW | Glow-worm Energy 12kW regular | £786.99 | 7 | View |
12kW | Ideal Logic Heat H12 | £729.21 | 2 | View |
12kW | Ideal Logic Max Heat H12 | £874.99 | 10 | View |
12kW | Ideal Logic+ Plus Heat H12 | £768.35 | 7 | View |
12kW | Potterton Titanium 12 heat | £734.50 | 7 | View |
12kW | Vaillant ecoFIT pure 412 regular | £767.60 | 2 | View |
12kW | Vaillant ecoTEC plus 412 regular boiler | £822.91 | 5 | View |
12kW | Worcester Bosch Greenstar 12Ri | £851.24 | 5 | View |
15kW | Baxi 200 Heat 15 | £801.48 | 3 | View |
15kW | Baxi 400 Heat 15 | £810.13 | 5 | View |
15kW | Glow-worm Energy 15kW regular | £806.78 | 7 | View |
15kW | Ideal Logic+ Plus Heat H15 | £878.73 | 7 | View |
15kW | Ideal Logic Heat H15 | £766.75 | 2 | View |
15kW | Ideal Mexico HE 15 | £1,130.11 | 2 | View |
15kW | Ideal Logic Max Heat H15 | £961.25 | 10 | View |
15kW | Potterton Titanium 15 heat | £773.50 | 7 | View |
15kW | Vaillant ecoTEC plus 415 regular boiler | £882.29 | 5 | View |
15kW | Vaillant ecoFIT pure 415 regular | £802.06 | 2 | View |
15kW | Worcester Bosch Greenstar 15Ri | £857.23 | 5 | View |
18kW | Baxi 400 Heat 18 | £844.41 | 5 | View |
18kW | Baxi 200 Heat 18 | £786.25 | 3 | View |
18kW | Glow-worm Energy 18kW regular | £847.99 | 7 | View |
18kW | Ideal Mexico HE 18 | £1,221.85 | 2 | View |
18kW | Ideal Logic Heat H18 | £799.48 | 2 | View |
18kW | Ideal Logic+ Plus Heat H18 | £835.04 | 7 | View |
18kW | Ideal Logic Max Heat H18 | £951.04 | 10 | View |
18kW | Potterton Titanium 18 heat | £812.50 | 7 | View |
18kW | Vaillant ecoTEC plus 418 regular boiler | £993.73 | 5 | View |
18kW | Vaillant ecoFIT pure 418 regular | £876.04 | 2 | View |
18kW | Worcester Bosch Greenstar 18Ri | £917.75 | 5 | View |
21kW | Worcester Bosch Greenstar 21Ri | £1,028.88 | 5 | View |
24kW | Baxi 200 Heat 24 | £875.71 | 3 | View |
24kW | Baxi 400 Heat 24 | £899.49 | 5 | View |
24kW | Ideal Logic Heat H24 | £837.56 | 2 | View |
24kW | Ideal Mexico HE 24 | £1,688.56 | 2 | View |
24kW | Ideal Logic Max Heat H24 | £985.46 | 10 | View |
24kW | Ideal Logic+ Plus Heat H24 | £875.46 | 7 | View |
24kW | Potterton Titanium 24 heat | £851.50 | 7 | View |
24kW | Vaillant ecoTEC plus 424 regular boiler | £1,055.19 | 5 | View |
24kW | Worcester Bosch Greenstar 24Ri | £972.35 | 5 | View |
25kW | Glow-worm Ultimate 3 25kW regular | £802.94 | 5 | View |
25kW | Glow-worm Energy 25kW regular | £883.99 | 7 | View |
25kW | Vaillant ecoFIT pure 425 regular | £952.06 | 2 | View |
27kW | Worcester Bosch Greenstar 27Ri | £1,090.69 | 5 | View |
30kW | Baxi 200 Heat 30 | £893.94 | 3 | View |
30kW | Baxi 400 Heat 30 | £976.50 | 5 | View |
30kW | Glow-worm Energy 30kW regular | £927.93 | 7 | View |
30kW | Ideal Mexico HE 30 | £2,074.00 | 2 | View |
30kW | Ideal Logic Heat H30 | £953.23 | 2 | View |
30kW | Ideal Logic Max Heat H30 | £1,156.25 | 10 | View |
30kW | Ideal Logic+ Plus Heat H30 | £993.30 | 7 | View |
30kW | Vaillant ecoFIT pure 430 regular | £1,012.48 | 2 | View |
30kW | Vaillant ecoTEC plus 430 regular boiler | £1,109.35 | 5 | View |
30kW | Worcester Bosch Greenstar FS 30CDi Regular | £1,732.88 | 5 | View |
30kW | Worcester Bosch Greenstar 30Ri | £1,136.60 | 5 | View |
30kW | Worcester Bosch Greenstar 30CDi Classic Regular | £1,216.28 | 5 | View |
32kW | Potterton Titanium 32 heat | £877.50 | 7 | View |
35kW | Vaillant ecoFIT pure 435 regular | £1,495.81 | 2 | View |
35kW | Vaillant ecoTEC plus 435 regular boiler | £1,597.91 | 5 | View |
36kW | Ideal Mexico HE 36 | £2,857.16 | 2 | View |
40kW | Worcester Bosch Greenstar 40CDi Classic Regular | £1,690.98 | 5 | View |
42kW | Worcester Bosch Greenstar FS 42CDi Regular | £2,363.59 | 5 | View |
Leave a Reply