Heat Only Boiler Guide: Prices, Pros & Cons & Leading Brands

There are many boiler brands around today that offer heat only boilers, which are available with different features and in varying power outputs. Heat only boiler prices vary considerably based on brand, model and output, with the typical cost ranging from £390 to over £2,300. You’re also likely to spend between £600 and £1,500 on the installation, making the total cost anything from £990 to £3,800.

If you’re thinking about upgrading to a new heat only boiler, we recommend you compare prices to give yourself the best chance of saving money on the boiler and installation costs. But before you do this, you also need to weigh up the pros and cons of installing a heat only boiler to ensure you choose the right type of boiler for your property and lifestyle.

By reading our guide, you can find out how heat only boilers work, compare heat only boiler prices and discover the advantages and disadvantages of purchasing one for your home.

How Do Heat Only Boilers Work?

Like system boilers, heat only boilers require a separate cylinder for storing hot water because they work on the principle of stored water. They also need a cold water storage tank that gets water from the mains supply, as well as a feed and expansion tank to ensure the right water level is maintained. The cold water tank in your loft feeds the boiler so that it can heat up the water, and a pump sends the hot water to the storage cylinder (usually located in an airing cupboard). It is the job of the cylinder to provide hot water for your taps and radiators.

Otherwise known as conventional, traditional or regular boilers, heat only boilers have been around much longer than combi and system boilers. As heat only boilers require separate tanks and an additional cylinder, they are best suited to homes with traditional heating and hot water systems in place. These boilers are also good for households with large hot water requirements and properties in areas where water pressure is low.

Heat Only Boiler Advantages and Disadvantages

One of the biggest advantages of installing a heat only boiler is that it can meet the heating and hot water needs of large properties, however, it can be more expensive to run. To determine whether you should purchase a heat only boiler, it’s important to familiarise yourself with all of the advantages and drawbacks.

Advantages

Can cope well with high hot water demands:All heat only boilers use a cylinder to store hot water to enable them to provide plenty of hot water to multiple taps, baths and showers simultaneously. This is ideal if you have a large home with more than one bathroom and typically use a lot of hot water from several taps at once.

Perfect for homes with a traditional system: If you already have a traditional heating and hot water system, a replacement heat only boiler is probably the best option for your home as it will require less work to install. A heat only boiler will also be a good replacement if you have an old radiator system – which will struggle to cope with a combi or system boiler because they both deliver high water pressure levels.

Lower energy bills: Heat only boilers are a lot more efficient than they used to be, with the majority achieving A ratings for energy efficiency. By replacing an old heat only boiler with a modern model, you could reduce the amount of energy you waste and save money on your bills.

Compatible with solar thermal systems: When using a heat only boiler with a solar thermal system, you can cut down your carbon emissions even more and reduce your energy costs even further.

Disadvantages

More loft and storage space is required:Since heat only boilers must be installed alongside tanks in the loft and a cylinder in the airing cupboard, they require a lot of storage space. This could be a problem if you live in a flat or small home where there is no extra space available.

Hot water is limited to how much your cylinder can hold: With a heat only boiler, the hot water is stored in a cylinder until you need to use it. You could run out of hot water if you use a lot at once, and you will need to wait for the cylinder to refill and heat up the water before having access to more. Hot water cylinders are available in a huge range of capacities though, so you could avoid running out of hot water if you have the right size installed.

No access to instant hot water: Another drawback to the water needing to be stored is that hot water is not instant. Instead, you will need to decide ahead of time when you are going to use your hot water. Some heat only boilers come with built-in controls (or optional controls) that allow you to programme the hot water timing to fit around your requirements.

More expensive to install: As heat only boilers requiremore pipework anda number of additional components (tanks and a cylinder), installation can take longer and be more expensive.  

Heat Only Boiler Prices

The amount you will need to spend on a heat only boiler will depend on your chosen model and its size, as well as the manufacturer. Most brands offer different heat only boiler models, which are designed to suit different needs and households.

Below are some comparison tables that enable you to compare heat only models from different boiler brands to give you a better idea of prices. The prices listed include VAT but exclude the cost of installation.

Worcester Bosch

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
Greenstar 24 Ri Regular	H - 600 mm W - 390 mm D - 270 mm	24 kw	N/A		£ 915.93
Greenstar 30 CDi Classic Regular	H - 760 mm W - 440 mm D - 360 mm	30 kw	N/A		£ 1,134.00
Greenstar FS 30 CDi Regular	H - 855 mm W - 440 mm D - 600 mm	30 kw	N/A		£ 1,155.80
Greenstar Danesmoor 25 Regular	H - 855 mm W - 370 mm D - 600 mm	25 kw	N/A		£1,570.80
Greenstar Danesmoor Utility 32 Regular	H - 855 mm W - 370 mm D - 600 mm	32 kw	N/A		£ 1,866.93
Greenstar Danesmoor External 32 Regular	H - 950 mm W - 565 mm D - 780 mm	32 kw	N/A		£ 2,220.00
Greenstar Utility 70 Regular	H - 1012 mm W - 520 mm D - 815 mm	70 kw	N/A		£ 2,268.00

Ideal

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
Logic Heat 24	H - 700 mm W - 395 mm D - 278 mm	24 kw	N/A		£ 790.50
Logic + Heat 30	H - 700 mm W - 395 mm D - 278 mm	30 kw	N/A		£ 995.99
Logic Max Heat 24	H - 700 mm W - 395 mm D - 278 mm	24 kw	N/A		£ 1,050.82
Mexico HE 30 Heat	H - 850 mm W - 450 mm D - 530 mm	30 kw	N/A		£ 1,959.83

Vokera

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
Easi-Flo Plus Water Heater	H - 640 mm W - 400 mm D - 246 mm	28 kw	11.8 l/min		£ 390.00
Mynute VHE 20	H - 740 mm W - 400 mm D - 338 mm	20 kw	N/A		£ 492.00

Keston

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
Keston Heat 45	H - 850 mm W - 500 mm D - 360 mm	45 kw	N/A		£2,340.87

Viessmann

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
Vitodens 100-W Open Vent 26	H - 600 mm W - 375 mm D - 285 mm	26 kw	N/A		£ 961.58

Vaillant

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
ecoFIT Plus Regular 25	H - 6000 mm W - 375 mm D - 295 mm	25 kw	N/A		£ 858.00
ecoTEC Plus Regular 30	H - 6000 mm W - 375 mm D - 320 mm	30 kw	N/A		£ 1,014.39

Baxi

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
400 Heat 30	H - 625 mm W - 370 mm D - 270 mm	30 kw	N/A		£ 834.00
200 Heat 24	H - 625 mm W - 370 mm D - 270 mm	24 kw	N/A		£ 849.41
EcoBlue Heat 24	H - 625 mm W - 370 mm D - 270 mm	24 kw	N/A		£ 911.58
EcoBlue Advance Heat 30	H - 625 mm W - 370 mm D - 270 mm	30 kw	N/A		£ 981.09

Potterton

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
Assure Heat 25	H - 700 mm W - 390 mm D - 270 mm	25 kw	N/A		£ 796.79
Promax SL Heat 18	H - 600 mm W - 390 mm D - 280 mm	18 kw	N/A		£ 803.58
Titanium Heat 30	H - 625 mm W - 370 mm D - 270 mm	30 kw	N/A		£ 842.40
Ultra Heat 24	H - 626 mm W - 370 mm D - 270 mm	24 kw	N/A		£ 1,000.00
Promax Store 90	H - 1544 mm W - 550 mm D - 600 mm	90 kw	N/A		£ 1,894.92

Glow-Worm

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
Ultimate3 Regular	H - 600 mm W - 375 mm D - 280 mm	25 kw	N/A		£ 870.00
Easicom3 Regular	H - 600 mm W - 375 mm D - 280 mm	25 kw	N/A		£ 887.92
Energy Regular 30	H - 600 mm W - 375 mm D - 280 mm	30 kw	N/A		£ 900.28

Ariston

MODEL	DIMENSIONS	OUTPUT	MAX FLOW RAT	EFFICIENCY	TYPICAL PRICE
Clas HE Regular	H - 595 mm W - 400 mm D - 295 mm	24 kw	N/A		£ 640.95

Don’t forget: Prior to making any decisions, you must ask a Gas Safe engineer to help you determine which heat only boiler model and size is right for your home.