What type of boiler system do I need?
With the constant development of building technologies, there is a greater range of options than ever before when considering the source of heat you will use to provide hot water and heating to your property. The various different options can be bewildering at times and include all sorts of options from air or ground source heat pumps, through gas boilers to oil, electric or even solid fuelled boilers. The easy access to mains gas in South-West London, however, means that the best option is invariably a gas powered boiler.
Broadly speaking, there are three types of gas boiler – combination (often called combi) boilers, closed vented (mains pressure) and open vented (gravity) system boilers. So in this blog article let’s try and work out the pros and cons of these three options.
Open-vented (gravity) system boilers
Open-vented system boilers are the traditional system with tanks of water in the loft, a hot water cylinder (usually in an airing cupboard or similar) and a separate boiler. Unless the system has been installed recently then this will almost certainly be the existing system in your home.
If you are Boiler Repairs Leyland an existing regular boiler which has broken down then this will clearly be what to install. If, however, you are installing a new heating / hot water system we would generally advise one of the other options in order to maximise space. The tanks in the loft clearly inhibit loft conversions and (if poorly insulated) pipes have been known to freeze in winter. Even if space can be made for the tanks there will not be an option for plumbing / heating in the loft.
Another downside to open-vented systems is that they require a difference in height between the bottom of the water tank in the loft and the hot water outlet to generate pressure using gravity. This distance is known as the head of water and if it is less than 1 metre, which would happen if you were to install a shower at loft level, then you might get nothing more than a trickle from the shower head. This is why showers in houses with open-vented systems often have to have their own pump to generate enough pressure to take a shower.
A regular boiler may be the best option for replacing an existing boiler if the property has an older radiator system, as it might not be able to cope with the higher water pressure that is delivered by system or combi boilers that work off mains pressure. This issue can be alleviated, however, by pressure-testing the existing system to identify any leaks at an early stage.