Regular Boilers
Also known as traditional or heat only boilers, regular boiler systems are made up of a number of components such as hot water cylinder, cold water storage cistern and also a feed and expansion cistern for the central heating.
A regular boiler is most commonly found in older properties. Although unlikely to install this style of boiler system today, it is common to replace individual components.
Advantages of a regular boiler system
- As water is stored within the cylinder and cistern, multiple water outlets can be used simultaneously with no effect on water pressure or temperature.
- The hot water cylinder is usually installed with an electric immersion heater. In the event of the heating system breaking down, the immersion can still provide hot water.
Disadvantages of a regular boiler system
- A regular boiler system has many components. There is the boiler, usually in a kitchen, hot water cylinder usually in an airing cupboard and the cold water storage that is ually in the loft. These are large items that are not ideal for smaller dwellings or those who prefer space saving living.
- As the hot water cylinder does not have the most up to date methods of insulation, this may mean that it has to be heated up more than once a day.
- As cold water is stored in the loft and fed to the cylinder by gravity, water pressure can be quite low. This can cause shower pressure to drop and often require booster pumps to perform effectively. In many cases it can be more beneficial to install a stand-alone electric shower.
System Boilers
A system boiler works in a simliar way to a regular boiler; however, the system boiler contains a number of additional parts such as the central heating pump, pressure relief valve and expansion vessel. This replaces the feed and expansion vessel usually located in the loft.
The boiler still needs a hot water cylinder, it is however unvented and supplies mains pressure hot water to the taps.
The system as a whole is more compact, making it more suitable to smaller homes.
System boilers are the most commonly installed boiler in new build homes. It is also common for regular boiler systems to be upgraded to system boilers.
Advantages of a system boiler
- The unvented hot water cylinder allows multiple taps, showers or baths to be used at once without experiencing a drop in pressure or temperature.
- As the system uses mains pressure it doesn't require a cold water storage cistern in the loft which saves on space.
- Unvented cylinders are well insulated by the manufacturer meaning they store water hotter for much longer than traidtional cylinders, often days longer.
- Immersion heaters are often installed in unvented cylinders, meaning should a boiler break down, then hot water is still available.
Disadvantages of a system boiler
- System boilers require space for the boiler and cylinder which is more than a combi boiler but much less than a traditional regular boiler.
- Unvented cylinders incorporate safety devices and an expansion vessel and require an annual safety check and service, this can be done at the same time as a boiler service.
Combi Boilers
Combination boilers are highly efficient and compact, making them ideal for smaller homes. The name "combi" - short for "combination" - comes from the fact that they are capable of providing instant hot water and central heating from the same unit.
Combi boilers heat water directly from the mains so it doesn't need a hot water cylinder in the airing cupboard or cold water cistern in the loft space, a great advantage for smaller homes.
It's quite common for homes with older regular systems to be converted to combi systems.
The process is straight forward and with the removal of the hot water cylinder and cisterns, provides more storage space in the airing cupboard and loft space.
Advantages of a combi boiler system
- Due to their compact size they are ideal for smaller homes as they do not require hot water cylinders, storage tanks and far less pipework and controls.
- As you only heat the water you need, a combi boiler can be more efficient, saving energy and money.
- Providing the property has an average water pressure and a good flow rate (litres per minute), you should maintain an equal pressure in all taps and showers, providing the boiler is correctly specified.
- You have hot water on demand and this is unlimited as you don't have to wait for a cylinder to heat up.
Disadvantages of a combi boiler system
- With a combi boiler you can only run one shower or bath at a time, unless you install a much larger combi and have excellent water pressure and flow rate feed into the home.
- As there is no hot water cylinder, you do not have an immersion heater, if your boiler does break down then you are without both heat and hot water until it is fixed.