What to consider when buying a gas boiler

When looking for a suitable heat generator, many homeowners still choose gas heating. This is also confirmed by official figures: About 95 percent of all appliances in operation in the UK use gas to generate heat. The operation of such a system requires some prerequisites to be fulfilled.

Gas connection for trouble-free operation

One of the advantages of gas heating is that owners of the system do not have to store the fuel. After all, in most cases the natural gas comes directly from the connection tap and thus enables extremely high operating comfort - at least in most cases. In the UK the gas supply network is well established. However, there can be no question of complete coverage with gas connection. Especially in rural areas, the laying of the gas pipes is not always an option.  

LPG tank for the use of LPG

Connection to the local gas supply is not necessary if the gas boiler burns LPG instead of natural gas. These are gases, some of which are liquefied under very high pressure. The best-known types of liquefied petroleum gas are butane and propane gases as well as LPG (liquefied petroleum gas) and LNG (natural gas liquids). LPG has a higher energy content than natural gas. For a gas boiler it means that it needs less fuel to produce the same amount of heat. If you want to buy a gas boiler that runs on LPG, you need a tank to store the fuel. This can either be installed above ground or buried underground.

Viessmann Vitodens, Gas Boiler range

Which boiler is the best for you?

Requirements for operating a gas condensing boiler

System designed for low flow temperature

The special feature of condensing technology is the use of the condensation heat produced. This occurs when the combustion gases cool down and the water vapour releases the hidden heat. In order for condensation to occur, the system should operate with the lowest possible flow temperatures. In concrete terms, this means that the heating water flowing from the radiators back to the boiler must be as cool as possible. This is the only way to make the hot exhaust gases condense. Underfloor heating and large-area radiators are particularly suitable for this mode of operation.

Viessmann stainless steel heat exchanger.
How to fix a broken boiler condensate pipe

Condensate drainage must be available

The use of a gas condensing boiler produces condensate. The condensate drain must be provided with an outlet for its removal. The slightly acidic condensate can easily be discharged into the normal sewage system. 

Not sure which product you need? Use our simple tool.

Man contemplating which boiler to buy for his home

Which gas boiler suits me?

Before homeowners buy a gas boiler, it is advisable to get an overview of the large number of models and their advantages.  If homeowners only require a small amount of heat, they can usually use a very compact wall-mounted unit that can even fit into a wall cupboard. Slightly wider are combi boilers with built-in DHW cylinders, which ensure a constant and high level of DHW convenience. Gas condensing boilers with integrated solar cylinders are the device of choice for those who plan to use solar energy from the outset.

For use in large buildings or industrial plants, gas boilers in larger output ranges are an option. They can use condensing technology and, thanks to cascade functions, achieve a nominal heat output of up to 2,000 kW.