Combi boilers are connected to the mains cold water supply and produce heat water on demand. when turning on a heating control or starting the hot water tap the boiler gets ignited and burns fuel to provide the required demand, this fuel will produce flames inside the boiler which produce heat. That heat is absorbed by parts known as heat exchangers.

As the boiler takes in water from the main water supply, it sends water through a series of pipes inside the heat exchangers. These heat exchangers are then warmed up by the flames and as the water travels through these hot pipes, the water temperature rises.

Combi boilers have a range of benefits and for many homes, they are the perfect solution. Some of the advantages of a combi boiler are as follows:

• Space saving – no need for a separate water tank
• Away from sight – everything is hidden away in one unit
• Money saving – energy efficiency also means lower bills
• Energy efficient – new models boast over 90% efficiency

Things to keep in mind before purchasing a combi boiler: Despite the many benefits of the combi, there are a few things you need to consider before you install one.

Pressure problems – functionality depends on mains
pressure, so they won’t work as well if you have poor flow rates or incoming water pressure

Not for larger homes – the flow rate drops if you want hot water in more than one place, so they’re not a great idea if you have more than one bathroom and people often shower at the same time

Not always compatible with old pipework
If you wish to upgrade a very old heating system, perhaps in an older house, you need to consider whether the existing pipework will be compatible with the new, more powerful boiler.